diff --git a/core/src/main/java/dev/morphia/DatastoreImpl.java b/core/src/main/java/dev/morphia/DatastoreImpl.java
index 0f03133fa91..fa5286e7b6c 100644
--- a/core/src/main/java/dev/morphia/DatastoreImpl.java
+++ b/core/src/main/java/dev/morphia/DatastoreImpl.java
@@ -48,6 +48,7 @@
 import dev.morphia.mapping.Mapper;
 import dev.morphia.mapping.MappingException;
 import dev.morphia.mapping.ShardKeyType;
+import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.EnumCodecProvider;
 import dev.morphia.mapping.codec.MorphiaCodecProvider;
 import dev.morphia.mapping.codec.MorphiaMapCodecProvider;
@@ -98,6 +99,7 @@
 public class DatastoreImpl implements AdvancedDatastore {
     private static final Logger LOG = LoggerFactory.getLogger(Datastore.class);
     private final MongoClient mongoClient;
+    private final Conversions conversions;
     private final Mapper mapper;
     private final QueryFactory queryFactory;
     private final CodecRegistry codecRegistry;
@@ -108,7 +110,8 @@ public class DatastoreImpl implements AdvancedDatastore {
     public DatastoreImpl(MongoClient client, MorphiaConfig config) {
         this.mongoClient = client;
         this.database = mongoClient.getDatabase(config.database());
-        this.mapper = new Mapper(config);
+        this.conversions = new Conversions(config.classLoader());
+        this.mapper = new Mapper(config, conversions);
         this.queryFactory = mapper.getConfig().queryFactory();
         importModels();
 
@@ -142,12 +145,23 @@ public DatastoreImpl(MongoClient client, MorphiaConfig config) {
     public DatastoreImpl(DatastoreImpl datastore) {
         this.mongoClient = datastore.mongoClient;
         this.database = mongoClient.getDatabase(datastore.mapper.getConfig().database());
+        this.conversions = datastore.conversions;
         this.mapper = datastore.mapper.copy();
         this.queryFactory = datastore.queryFactory;
         this.operations = datastore.operations;
         codecRegistry = buildRegistry();
     }
 
+    /**
+     * @return the Conversions instance used by this Datastore
+     * @morphia.internal
+     * @hidden
+     */
+    @MorphiaInternal
+    public Conversions getConversions() {
+        return conversions;
+    }
+
     private CodecRegistry buildRegistry() {
         morphiaCodecProviders.add(new MorphiaCodecProvider(this));
 
@@ -641,7 +655,7 @@ public <T> void refresh(T entity) {
                 .iterator()
                 .next();
 
-        refreshCodec.decode(new DocumentReader(id), DecoderContext.builder().checkedDiscriminator(true).build());
+        refreshCodec.decode(new DocumentReader(id, conversions), DecoderContext.builder().checkedDiscriminator(true).build());
     }
 
     @Override
diff --git a/core/src/main/java/dev/morphia/aggregation/AggregationImpl.java b/core/src/main/java/dev/morphia/aggregation/AggregationImpl.java
index 438c89cb263..b0dc49125ee 100644
--- a/core/src/main/java/dev/morphia/aggregation/AggregationImpl.java
+++ b/core/src/main/java/dev/morphia/aggregation/AggregationImpl.java
@@ -354,7 +354,7 @@ public Aggregation<T> addStage(Stage stage) {
         return this;
     }
 
-    private static class MappingCursor<R> implements MongoCursor<R> {
+    private class MappingCursor<R> implements MongoCursor<R> {
         private final MongoCursor<Document> results;
         private final Codec<R> codec;
         private final String discriminator;
@@ -403,7 +403,7 @@ public ServerAddress getServerAddress() {
 
         private R map(Document next) {
             next.remove(discriminator);
-            return codec.decode(new DocumentReader(next), DecoderContext.builder().build());
+            return codec.decode(new DocumentReader(next, datastore.getConversions()), DecoderContext.builder().build());
         }
     }
 
diff --git a/core/src/main/java/dev/morphia/config/ManualMorphiaConfig.java b/core/src/main/java/dev/morphia/config/ManualMorphiaConfig.java
index c750bae46db..4b3e2e40df5 100644
--- a/core/src/main/java/dev/morphia/config/ManualMorphiaConfig.java
+++ b/core/src/main/java/dev/morphia/config/ManualMorphiaConfig.java
@@ -48,6 +48,7 @@ public class ManualMorphiaConfig implements MorphiaConfig {
     Boolean storeEmpties;
     Boolean storeNulls;
     UuidRepresentation uuidRepresentation;
+    ClassLoader classLoader;
 
     /**
      * @hidden
@@ -78,6 +79,7 @@ public ManualMorphiaConfig(MorphiaConfig base) {
         storeEmpties = base.storeEmpties();
         storeNulls = base.storeNulls();
         uuidRepresentation = base.uuidRepresentation();
+        classLoader = base.classLoader();
     }
 
     /**
@@ -95,6 +97,11 @@ public static ManualMorphiaConfig configure(MorphiaConfig base) {
         return new ManualMorphiaConfig(base);
     }
 
+    @Override
+    public ClassLoader classLoader() {
+        return orDefault(classLoader, Thread.currentThread().getContextClassLoader());
+    }
+
     @Override
     public Boolean applyCaps() {
         return orDefault(applyCaps, FALSE);
diff --git a/core/src/main/java/dev/morphia/config/MorphiaConfig.java b/core/src/main/java/dev/morphia/config/MorphiaConfig.java
index 35635739123..e5234e2a61d 100644
--- a/core/src/main/java/dev/morphia/config/MorphiaConfig.java
+++ b/core/src/main/java/dev/morphia/config/MorphiaConfig.java
@@ -53,6 +53,16 @@ static MorphiaConfig load() {
         return load(MorphiaConfigHelper.MORPHIA_CONFIG_PROPERTIES);
     }
 
+    /**
+     * Tries to load a configuration from the default location using the given classloader.
+     *
+     * @param classLoader the classloader to use when loading resources from the classpath
+     * @return the loaded config
+     */
+    static MorphiaConfig load(ClassLoader classLoader) {
+        return load(MorphiaConfigHelper.MORPHIA_CONFIG_PROPERTIES, classLoader);
+    }
+
     /**
      * Parses and loads the configuration found at the given location
      *
@@ -62,18 +72,55 @@ static MorphiaConfig load() {
      * @since 3.0
      */
     static MorphiaConfig load(String path) {
-        List<ConfigSource> configSources = classPathSources(path, currentThread().getContextClassLoader());
+        return load(path, currentThread().getContextClassLoader());
+    }
+
+    /**
+     * Parses and loads the configuration found at the given location
+     *
+     * @param path        the location of the configuration to load. This can be a file path, a classpath resource, a URL, etc.
+     * @param classLoader the classloader to use when loading resources from the classpath
+     *
+     * @return the loaded configuration
+     * @since 3.0
+     */
+    static MorphiaConfig load(String path, ClassLoader classLoader) {
+        List<ConfigSource> configSources = classPathSources(path, classLoader);
         if (configSources.isEmpty()) {
             LoggerFactory.getLogger(MorphiaConfig.class).warn(Sofia.missingConfigFile(path));
-            return new ManualMorphiaConfig();
+            return new ManualMorphiaConfig().classLoader(classLoader);
         }
-        return new SmallRyeConfigBuilder()
+        MorphiaConfig config = new SmallRyeConfigBuilder()
                 .addDefaultInterceptors()
                 .withMapping(MorphiaConfig.class)
                 .withSources(configSources)
                 .addDefaultSources()
                 .build()
                 .getConfigMapping(MorphiaConfig.class);
+        return config.classLoader(classLoader);
+    }
+
+    /**
+     * The ClassLoader to use for class resolution. Defaults to the current thread's context ClassLoader.
+     *
+     * @return the ClassLoader
+     * @since 2.5
+     */
+    default ClassLoader classLoader() {
+        return currentThread().getContextClassLoader();
+    }
+
+    /**
+     * Updates this configuration with a new ClassLoader and returns a new instance. The original instance is unchanged.
+     *
+     * @param value the new ClassLoader
+     * @return a new instance with the updated configuration
+     * @since 2.5
+     */
+    default MorphiaConfig classLoader(ClassLoader value) {
+        var newConfig = new ManualMorphiaConfig(this);
+        newConfig.classLoader = value;
+        return newConfig;
     }
 
     /**
diff --git a/core/src/main/java/dev/morphia/mapping/DiscriminatorLookup.java b/core/src/main/java/dev/morphia/mapping/DiscriminatorLookup.java
index 58aee312782..86ca7a186a2 100644
--- a/core/src/main/java/dev/morphia/mapping/DiscriminatorLookup.java
+++ b/core/src/main/java/dev/morphia/mapping/DiscriminatorLookup.java
@@ -40,6 +40,11 @@
 public final class DiscriminatorLookup {
     private final Map<String, String> discriminatorClassMap = new ConcurrentHashMap<>();
     private final Set<String> packages = new ConcurrentSkipListSet<>();
+    private final ClassLoader classLoader;
+
+    public DiscriminatorLookup(ClassLoader classLoader) {
+        this.classLoader = classLoader;
+    }
 
     /**
      * Adds a model to the map
@@ -64,7 +69,7 @@ public void addModel(EntityModel entityModel) {
     public Class<?> lookup(String discriminator) {
         if (discriminatorClassMap.containsKey(discriminator)) {
             try {
-                return Class.forName(discriminatorClassMap.get(discriminator), true, Thread.currentThread().getContextClassLoader());
+                return Class.forName(discriminatorClassMap.get(discriminator), true, classLoader);
             } catch (ClassNotFoundException e) {
                 throw new MappingException(e.getMessage(), e);
             }
@@ -85,7 +90,7 @@ public Class<?> lookup(String discriminator) {
     private Class<?> getClassForName(String discriminator) {
         Class<?> clazz = null;
         try {
-            clazz = Class.forName(discriminator, true, Thread.currentThread().getContextClassLoader());
+            clazz = Class.forName(discriminator, true, classLoader);
         } catch (ClassNotFoundException e) {
             // Ignore
         }
diff --git a/core/src/main/java/dev/morphia/mapping/InstanceCreatorFactory.java b/core/src/main/java/dev/morphia/mapping/InstanceCreatorFactory.java
index 04b5cca0ae2..998ff85c183 100644
--- a/core/src/main/java/dev/morphia/mapping/InstanceCreatorFactory.java
+++ b/core/src/main/java/dev/morphia/mapping/InstanceCreatorFactory.java
@@ -1,5 +1,6 @@
 package dev.morphia.mapping;
 
+import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.MorphiaInstanceCreator;
 
 /**
@@ -8,7 +9,8 @@
 public interface InstanceCreatorFactory {
 
     /**
+     * @param conversions the Conversions instance to use
      * @return a new ClassAccessor instance
      */
-    MorphiaInstanceCreator create();
+    MorphiaInstanceCreator create(Conversions conversions);
 }
diff --git a/core/src/main/java/dev/morphia/mapping/InstanceCreatorFactoryImpl.java b/core/src/main/java/dev/morphia/mapping/InstanceCreatorFactoryImpl.java
index 420779d8413..3e65bd84931 100644
--- a/core/src/main/java/dev/morphia/mapping/InstanceCreatorFactoryImpl.java
+++ b/core/src/main/java/dev/morphia/mapping/InstanceCreatorFactoryImpl.java
@@ -1,9 +1,10 @@
 package dev.morphia.mapping;
 
 import java.lang.reflect.Constructor;
-import java.util.function.Supplier;
+import java.util.function.Function;
 
 import dev.morphia.annotations.internal.MorphiaInternal;
+import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.MorphiaInstanceCreator;
 import dev.morphia.mapping.codec.pojo.EntityModel;
 import dev.morphia.mapping.internal.ConstructorCreator;
@@ -22,7 +23,7 @@ public class InstanceCreatorFactoryImpl implements InstanceCreatorFactory {
     private static final Logger LOG = LoggerFactory.getLogger(InstanceCreatorFactoryImpl.class);
 
     private final EntityModel model;
-    private Supplier<MorphiaInstanceCreator> creator;
+    private Function<Conversions, MorphiaInstanceCreator> creator;
 
     /**
      * Creates a factory for this type
@@ -35,20 +36,20 @@ public InstanceCreatorFactoryImpl(EntityModel model) {
     }
 
     @Override
-    public MorphiaInstanceCreator create() {
+    public MorphiaInstanceCreator create(Conversions conversions) {
         if (creator == null) {
             if (!model.getType().isInterface()) {
                 Constructor<?> constructor = ConstructorCreator.bestConstructor(model);
                 if (constructor != null) {
-                    creator = () -> new ConstructorCreator(model, constructor);
+                    creator = (c) -> new ConstructorCreator(model, constructor, c);
                 } else {
                     LOG.debug("using old creator approach: " + model.getType().getName());
                     try {
                         Constructor<?> declared = model.getType().getDeclaredConstructor();
-                        creator = () -> new NoArgCreator(declared);
+                        creator = (c) -> new NoArgCreator(declared);
                     } catch (NoSuchMethodException e) {
                         Constructor<?> full = ConstructorCreator.getFullConstructor(model);
-                        creator = () -> new ConstructorCreator(model, full);
+                        creator = (c) -> new ConstructorCreator(model, full, c);
                     }
                 }
             }
@@ -58,6 +59,6 @@ public MorphiaInstanceCreator create() {
             }
         }
 
-        return creator.get();
+        return creator.apply(conversions);
     }
 }
diff --git a/core/src/main/java/dev/morphia/mapping/Mapper.java b/core/src/main/java/dev/morphia/mapping/Mapper.java
index 81bd71d149a..2105387d7cd 100644
--- a/core/src/main/java/dev/morphia/mapping/Mapper.java
+++ b/core/src/main/java/dev/morphia/mapping/Mapper.java
@@ -29,6 +29,7 @@
 import dev.morphia.annotations.PrePersist;
 import dev.morphia.annotations.internal.MorphiaInternal;
 import dev.morphia.config.MorphiaConfig;
+import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.pojo.EntityModel;
 import dev.morphia.mapping.codec.pojo.EntityModelBuilder;
 import dev.morphia.mapping.codec.pojo.PropertyModel;
@@ -79,18 +80,21 @@ public class Mapper {
     private final MorphiaConfig config;
     private final DiscriminatorLookup discriminatorLookup;
     private final Object entityRegistrationMonitor = new Object();
+    private final Conversions conversions;
 
     /**
-     * Creates a Mapper with the given options.
+     * Creates a Mapper with the given options and Conversions instance.
      *
-     * @param config the config to use
+     * @param config      the config to use
+     * @param conversions the Conversions instance to use
      * @morphia.internal
      * @hidden
      */
     @MorphiaInternal
-    public Mapper(MorphiaConfig config) {
+    public Mapper(MorphiaConfig config, Conversions conversions) {
         this.config = config;
-        discriminatorLookup = new DiscriminatorLookup();
+        this.conversions = conversions;
+        discriminatorLookup = new DiscriminatorLookup(conversions.getClassLoader());
     }
 
     /**
@@ -100,7 +104,8 @@ public Mapper(MorphiaConfig config) {
      */
     public Mapper(Mapper other) {
         config = other.config;
-        discriminatorLookup = new DiscriminatorLookup();
+        conversions = other.conversions;
+        discriminatorLookup = new DiscriminatorLookup(other.getClassLoader());
         other.mappedEntities.values().forEach(entity -> clone(entity));
         listeners.addAll(other.listeners);
     }
@@ -173,6 +178,20 @@ public PropertyModel findIdProperty(Class<?> type) {
         return idField;
     }
 
+    public ClassLoader getClassLoader() {
+        return conversions.getClassLoader();
+    }
+
+    /**
+     * @return the Conversions instance used by this Mapper
+     * @morphia.internal
+     * @hidden
+     */
+    @MorphiaInternal
+    public Conversions getConversions() {
+        return conversions;
+    }
+
     /**
      * Gets the class as defined by any discriminator field
      *
@@ -618,7 +637,7 @@ private List<Class> getClasses(String packageName)
         try (ScanResult scanResult = classGraph.scan()) {
             for (ClassInfo classInfo : scanResult.getAllClasses()) {
                 try {
-                    classes.add(Class.forName(classInfo.getName(), true, Thread.currentThread().getContextClassLoader()));
+                    classes.add(Class.forName(classInfo.getName(), true, conversions.getClassLoader()));
                 } catch (Throwable ignored) {
                 }
             }
diff --git a/core/src/main/java/dev/morphia/mapping/codec/ArrayFieldAccessor.java b/core/src/main/java/dev/morphia/mapping/codec/ArrayFieldAccessor.java
index 5027284e965..807aa2d7fcf 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/ArrayFieldAccessor.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/ArrayFieldAccessor.java
@@ -20,17 +20,20 @@ public class ArrayFieldAccessor extends FieldAccessor {
 
     private final TypeData<?> typeData;
     private final Class<?> componentType;
+    private final Conversions conversions;
 
     /**
      * Creates the accessor
      *
-     * @param typeData the type data
-     * @param field    the field
+     * @param typeData    the type data
+     * @param field       the field
+     * @param conversions the Conversions instance to use
      */
-    public ArrayFieldAccessor(TypeData<?> typeData, Field field) {
+    public ArrayFieldAccessor(TypeData<?> typeData, Field field, Conversions conversions) {
         super(field);
         this.typeData = typeData;
         componentType = field.getType().getComponentType();
+        this.conversions = conversions;
     }
 
     @Override
@@ -84,6 +87,6 @@ private Object convert(Object o, Class<?> type) {
 
             return newArray;
         }
-        return Conversions.convert(o, type);
+        return conversions.convert(o, type);
     }
 }
diff --git a/core/src/main/java/dev/morphia/mapping/codec/ClassCodec.java b/core/src/main/java/dev/morphia/mapping/codec/ClassCodec.java
index 6e8967e7d05..bfd3e9c6cc6 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/ClassCodec.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/ClassCodec.java
@@ -12,11 +12,16 @@
  * Defines a codec for Class references
  */
 public class ClassCodec implements Codec<Class> {
+    private final Conversions conversions;
+
+    public ClassCodec(Conversions conversions) {
+        this.conversions = conversions;
+    }
+
     @Override
     public Class decode(BsonReader reader, DecoderContext decoderContext) {
         try {
-            ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
-            return Class.forName(reader.readString(), true, classLoader);
+            return Class.forName(reader.readString(), true, conversions.getClassLoader());
         } catch (ClassNotFoundException e) {
             throw new MappingException(e.getMessage(), e);
         }
diff --git a/core/src/main/java/dev/morphia/mapping/codec/Conversions.java b/core/src/main/java/dev/morphia/mapping/codec/Conversions.java
index 4aa781e666e..4b5f6a7dcd0 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/Conversions.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/Conversions.java
@@ -9,6 +9,7 @@
 import java.util.Map;
 import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.BiFunction;
 import java.util.function.Function;
 
 import com.mongodb.lang.Nullable;
@@ -31,12 +32,30 @@
  * @morphia.internal
  */
 @MorphiaInternal
-public final class Conversions {
+public class Conversions {
     private static final Logger LOG = LoggerFactory.getLogger(Conversions.class);
 
-    private static final Map<Class<?>, Map<Class<?>, Function<?, ?>>> CONVERSIONS = new ConcurrentHashMap<>();
+    private final Map<Class<?>, Map<Class<?>, BiFunction<?, ClassLoader, ?>>> conversions = new ConcurrentHashMap<>();
+    private final ClassLoader classLoader;
 
-    static {
+    /**
+     * Creates a new Conversions instance with the given ClassLoader.
+     *
+     * @param classLoader the ClassLoader to use for class resolution
+     */
+    public Conversions(ClassLoader classLoader) {
+        this.classLoader = classLoader;
+        registerDefaults();
+    }
+
+    /**
+     * @return the ClassLoader used by this Conversions instance
+     */
+    public ClassLoader getClassLoader() {
+        return classLoader;
+    }
+
+    private void registerDefaults() {
         registerStringConversions();
 
         register(Binary.class, byte[].class, Binary::getData);
@@ -81,10 +100,7 @@ public final class Conversions {
         });
     }
 
-    private Conversions() {
-    }
-
-    private static void registerStringConversions() {
+    private void registerStringConversions() {
         register(String.class, BigDecimal.class, BigDecimal::new);
         register(String.class, ObjectId.class, ObjectId::new);
         register(String.class, Character.class, s -> {
@@ -97,9 +113,9 @@ private static void registerStringConversions() {
             }
         });
         register(Class.class, String.class, Class::getName);
-        register(String.class, Class.class, className -> {
+        registerWithClassLoader(String.class, Class.class, (className, cl) -> {
             try {
-                return Thread.currentThread().getContextClassLoader().loadClass(className);
+                return cl.loadClass(className);
             } catch (ClassNotFoundException e) {
                 throw new MappingException(e.getMessage(), e);
             }
@@ -124,24 +140,7 @@ private static void registerStringConversions() {
     }
 
     /**
-     * Register a conversion between two types. For example, to register the conversion of {@link Date} to a {@link Long}, this method
-     * could be invoked as follows:
-     * <code>
-     * register(Date.class, Long.class, Date::getTime);
-     * </code>
-     *
-     * @param source   the source type
-     * @param target   the target type
-     * @param function the function that performs the conversion. This is often just a method reference.
-     * @param <S>      the source type
-     * @param <T>      the target type.
-     */
-    public static <S, T> void register(Class<S> source, Class<T> target, Function<S, T> function) {
-        register(source, target, function, null);
-    }
-
-    /**
-     * Attempts to convert a value to the given type
+     * Attempts to convert a value to the given type.
      *
      * @param value  the value to convert
      * @param target the target type
@@ -150,17 +149,15 @@ public static <S, T> void register(Class<S> source, Class<T> target, Function<S,
      */
     @SuppressWarnings({ "unchecked", "rawtypes" })
     @Nullable
-    public static <T> T convert(@Nullable Object value, Class<T> target) {
+    public <T> T convert(@Nullable Object value, Class<T> target) {
         if (value == null) {
             return (T) convertNull(target);
         }
-
         final Class<?> fromType = value.getClass();
         if (fromType.equals(target)) {
             return (T) value;
         }
-
-        final Function function = CONVERSIONS
+        final BiFunction function = conversions
                 .computeIfAbsent(fromType, (f) -> new ConcurrentHashMap<>())
                 .get(target);
         if (function == null) {
@@ -172,7 +169,7 @@ public static <T> T convert(@Nullable Object value, Class<T> target) {
             }
             return (T) value;
         }
-        return (T) function.apply(value);
+        return (T) function.apply(value, classLoader);
     }
 
     @Nullable
@@ -186,30 +183,70 @@ private static Object convertNull(Class<?> toType) {
     }
 
     /**
-     * Register a conversion between two types. For example, to register the conversion of {@link Date} to a {@link Long}, this method
-     * could be invoked as follows:
-     * <code>
-     * register(Date.class, Long.class, Date::getTime);
-     * </code>
+     * Register a conversion between two types.
      *
      * @param source   the source type
      * @param target   the target type
-     * @param function the function that performs the conversion. This is often just a method reference.
-     * @param warning  if non-null, this will be the message logged on the WARN level indicating the conversion is taking place.
+     * @param function the function that performs the conversion
      * @param <S>      the source type
-     * @param <T>      the target type.
+     * @param <T>      the target type
      */
-    public static <S, T> void register(Class<S> source, Class<T> target, Function<S, T> function,
+    public <S, T> void register(Class<S> source, Class<T> target, Function<S, T> function) {
+        register(source, target, function, null);
+    }
+
+    /**
+     * Register a conversion between two types.
+     *
+     * @param source   the source type
+     * @param target   the target type
+     * @param function the function that performs the conversion
+     * @param warning  if non-null, this will be logged on WARN level
+     * @param <S>      the source type
+     * @param <T>      the target type
+     */
+    public <S, T> void register(Class<S> source, Class<T> target, Function<S, T> function,
             @Nullable String warning) {
-        final Function<S, T> conversion = warning == null
+        // Wrap Function as BiFunction (ignore ClassLoader parameter)
+        BiFunction<S, ClassLoader, T> biFunction = (s, cl) -> function.apply(s);
+        registerWithClassLoader(source, target, biFunction, warning);
+    }
+
+    /**
+     * Register a conversion between two types with ClassLoader support.
+     *
+     * @param source   the source type
+     * @param target   the target type
+     * @param function the function that performs the conversion (receives ClassLoader)
+     * @param <S>      the source type
+     * @param <T>      the target type
+     */
+    public <S, T> void registerWithClassLoader(Class<S> source, Class<T> target,
+            BiFunction<S, ClassLoader, T> function) {
+        registerWithClassLoader(source, target, function, null);
+    }
+
+    /**
+     * Register a conversion between two types with ClassLoader support.
+     *
+     * @param source   the source type
+     * @param target   the target type
+     * @param function the function that performs the conversion (receives ClassLoader)
+     * @param warning  if non-null, this will be logged on WARN level
+     * @param <S>      the source type
+     * @param <T>      the target type
+     */
+    public <S, T> void registerWithClassLoader(Class<S> source, Class<T> target,
+            BiFunction<S, ClassLoader, T> function, @Nullable String warning) {
+        final BiFunction<S, ClassLoader, T> conversion = warning == null
                 ? function
-                : s -> {
+                : (s, cl) -> {
                     if (LOG.isWarnEnabled()) {
                         LOG.warn(warning);
                     }
-                    return function.apply(s);
+                    return function.apply(s, cl);
                 };
-        CONVERSIONS.computeIfAbsent(source, (Class<?> c) -> new HashMap<>())
+        conversions.computeIfAbsent(source, (Class<?> c) -> new HashMap<>())
                 .put(target, conversion);
     }
 
diff --git a/core/src/main/java/dev/morphia/mapping/codec/MorphiaCodecProvider.java b/core/src/main/java/dev/morphia/mapping/codec/MorphiaCodecProvider.java
index 4c02af5f766..c839003a6b2 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/MorphiaCodecProvider.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/MorphiaCodecProvider.java
@@ -36,6 +36,7 @@
 public class MorphiaCodecProvider implements CodecProvider {
     private final Map<Class<?>, Codec<?>> codecs = new HashMap<>();
     private final Mapper mapper;
+    private final Conversions conversions;
     private final List<PropertyCodecProvider> propertyCodecProviders = new ArrayList<>();
     private Datastore datastore;
 
@@ -47,6 +48,7 @@ public class MorphiaCodecProvider implements CodecProvider {
     public MorphiaCodecProvider(Datastore datastore) {
         this.datastore = datastore;
         this.mapper = datastore.getMapper();
+        this.conversions = mapper.getConversions();
 
         // Load user-provided custom codecs first, to prevent the defaults from overriding them.
         ServiceLoader<MorphiaPropertyCodecProvider> providers = ServiceLoader.load(MorphiaPropertyCodecProvider.class);
@@ -54,7 +56,7 @@ public MorphiaCodecProvider(Datastore datastore) {
             propertyCodecProviders.add(provider);
         });
 
-        propertyCodecProviders.addAll(List.of(new MorphiaMapPropertyCodecProvider(),
+        propertyCodecProviders.addAll(List.of(new MorphiaMapPropertyCodecProvider(datastore, conversions),
                 new MorphiaCollectionPropertyCodecProvider()));
     }
 
@@ -73,7 +75,7 @@ public <T> Codec<T> get(Class<T> type, CodecRegistry registry) {
         MorphiaCodec<T> codec = (MorphiaCodec<T>) codecs.get(type);
         if (codec == null && (mapper.isMapped(type) || mapper.isMappable(type))) {
             EntityModel model = mapper.getEntityModel(type);
-            codec = new MorphiaCodec<>(datastore, model, propertyCodecProviders, mapper.getDiscriminatorLookup(), registry);
+            codec = new MorphiaCodec<>(datastore, model, propertyCodecProviders, mapper.getDiscriminatorLookup(), registry, conversions);
             if (model.hasLifecycle(PostPersist.class) || model.hasLifecycle(PrePersist.class) || mapper.hasInterceptors()) {
                 codec.setEncoder(new LifecycleEncoder(codec));
             }
@@ -97,7 +99,7 @@ public <T> Codec<T> get(Class<T> type, CodecRegistry registry) {
     @Nullable
     public <T> Codec<T> getRefreshCodec(T entity, CodecRegistry registry) {
         EntityModel model = mapper.getEntityModel(entity.getClass());
-        return new MorphiaCodec<>(datastore, model, propertyCodecProviders, mapper.getDiscriminatorLookup(), registry) {
+        return new MorphiaCodec<>(datastore, model, propertyCodecProviders, mapper.getDiscriminatorLookup(), registry, conversions) {
             @Override
             protected EntityDecoder<T> getDecoder() {
                 return new EntityDecoder<>(this) {
diff --git a/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapCodec.java b/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapCodec.java
index c4a72e99513..a461ac0980f 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapCodec.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapCodec.java
@@ -34,11 +34,13 @@ public class MorphiaMapCodec implements Codec<Map> {
     private Supplier<Map> factory;
 
     private Datastore datastore;
+    private final Conversions conversions;
 
     private final Codec<?> valueCodec;
 
-    public MorphiaMapCodec(DatastoreImpl datastore, Class<?> clazz, Codec<?> valueCodec) {
+    public MorphiaMapCodec(DatastoreImpl datastore, Class<?> clazz, Codec<?> valueCodec, Conversions conversions) {
         this.datastore = datastore;
+        this.conversions = conversions;
         this.valueCodec = valueCodec;
         try {
             Constructor<?> ctor = clazz.getDeclaredConstructor();
@@ -78,7 +80,7 @@ public void encode(BsonWriter writer, Map map, EncoderContext encoderContext) {
         document(writer, () -> {
             for (Entry<?, ?> entry : ((Map<?, ?>) map).entrySet()) {
                 final Object key = entry.getKey();
-                writer.writeName(Conversions.convert(key, String.class));
+                writer.writeName(conversions.convert(key, String.class));
                 if (entry.getValue() == null) {
                     writer.writeNull();
                 } else {
diff --git a/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapCodecProvider.java b/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapCodecProvider.java
index 15bb34b189b..f968bd9cd71 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapCodecProvider.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapCodecProvider.java
@@ -32,7 +32,7 @@ public <T> Codec<T> get(Class<T> clazz, List<Type> typeArguments, CodecRegistry
             return (Codec<T>) new BsonDocumentCodec(registry);
         } else if (Map.class.isAssignableFrom(clazz) && !Document.class.isAssignableFrom(clazz)) {
             Class valueType = typeArguments.size() == 2 ? (Class) typeArguments.get(1) : Object.class;
-            return (Codec<T>) new MorphiaMapCodec(datastore, clazz, registry.get(valueType));
+            return (Codec<T>) new MorphiaMapCodec(datastore, clazz, registry.get(valueType), datastore.getConversions());
         }
         return null;
     }
diff --git a/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapPropertyCodecProvider.java b/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapPropertyCodecProvider.java
index 8b5f4f9ef6a..f5cb493988b 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapPropertyCodecProvider.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/MorphiaMapPropertyCodecProvider.java
@@ -6,6 +6,7 @@
 import java.util.Map;
 import java.util.Map.Entry;
 
+import dev.morphia.Datastore;
 import dev.morphia.annotations.internal.MorphiaInternal;
 import dev.morphia.mapping.codec.pojo.TypeData;
 
@@ -28,6 +29,14 @@
 @MorphiaInternal
 @SuppressWarnings("unchecked")
 class MorphiaMapPropertyCodecProvider extends MorphiaPropertyCodecProvider {
+    private final Datastore datastore;
+    private final Conversions conversions;
+
+    public MorphiaMapPropertyCodecProvider(Datastore datastore, Conversions conversions) {
+        this.datastore = datastore;
+        this.conversions = conversions;
+    }
+
     @Override
     public <T> Codec<T> get(TypeWithTypeParameters<T> type, PropertyCodecRegistry registry) {
         if (Map.class.isAssignableFrom(type.getType())) {
@@ -51,7 +60,7 @@ public <T> Codec<T> get(TypeWithTypeParameters<T> type, PropertyCodecRegistry re
         return null;
     }
 
-    private static class MapCodec<K, V> implements Codec<Map<K, V>> {
+    private class MapCodec<K, V> implements Codec<Map<K, V>> {
         private final Class<Map<K, V>> encoderClass;
         private final Class<K> keyType;
         private final Codec<V> codec;
@@ -67,7 +76,7 @@ public void encode(BsonWriter writer, Map<K, V> map, EncoderContext encoderConte
             document(writer, () -> {
                 for (Entry<K, V> entry : map.entrySet()) {
                     final K key = entry.getKey();
-                    writer.writeName(Conversions.convert(key, String.class));
+                    writer.writeName(conversions.convert(key, String.class));
                     if (entry.getValue() == null) {
                         writer.writeNull();
                     } else {
@@ -82,7 +91,7 @@ public Map<K, V> decode(BsonReader reader, DecoderContext context) {
             reader.readStartDocument();
             Map<K, V> map = getInstance();
             while (reader.readBsonType() != BsonType.END_OF_DOCUMENT) {
-                final K key = Conversions.convert(reader.readName(), keyType);
+                final K key = conversions.convert(reader.readName(), keyType);
                 if (reader.getCurrentBsonType() == BsonType.NULL) {
                     map.put(key, null);
                     reader.readNull();
diff --git a/core/src/main/java/dev/morphia/mapping/codec/MorphiaTypesCodecProvider.java b/core/src/main/java/dev/morphia/mapping/codec/MorphiaTypesCodecProvider.java
index 44a58c8f1df..c542efb9715 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/MorphiaTypesCodecProvider.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/MorphiaTypesCodecProvider.java
@@ -28,7 +28,7 @@ public MorphiaTypesCodecProvider(DatastoreImpl datastore) {
         addCodec(new MorphiaDateCodec(datastore));
         addCodec(new MorphiaLocalDateTimeCodec(datastore));
         addCodec(new MorphiaLocalTimeCodec());
-        addCodec(new ClassCodec());
+        addCodec(new ClassCodec(datastore.getConversions()));
         addCodec(new CenterCodec());
         addCodec(new KeyCodec(datastore));
         addCodec(new LocaleCodec());
diff --git a/core/src/main/java/dev/morphia/mapping/codec/pojo/EntityDecoder.java b/core/src/main/java/dev/morphia/mapping/codec/pojo/EntityDecoder.java
index 94f145bb77f..1210c389380 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/pojo/EntityDecoder.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/pojo/EntityDecoder.java
@@ -18,7 +18,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import static dev.morphia.mapping.codec.Conversions.convert;
 import static java.lang.String.format;
 
 /**
@@ -71,7 +70,7 @@ protected void decodeModel(BsonReader reader, DecoderContext decoderContext,
             } catch (BsonInvalidOperationException e) {
                 mark.reset();
                 final Object value = morphiaCodec.getDatastore().getCodecRegistry().get(Object.class).decode(reader, decoderContext);
-                instanceCreator.set(convert(value, model.getTypeData().getType()), model);
+                instanceCreator.set(morphiaCodec.getConversions().convert(value, model.getTypeData().getType()), model);
             }
         } else {
             reader.skipValue();
@@ -118,7 +117,7 @@ protected Codec<T> getCodecFromDocument(BsonReader reader, boolean useDiscrimina
     }
 
     protected MorphiaInstanceCreator getInstanceCreator() {
-        return classModel.getInstanceCreator();
+        return classModel.getInstanceCreator(morphiaCodec.getConversions());
     }
 
     protected MorphiaCodec<T> getMorphiaCodec() {
diff --git a/core/src/main/java/dev/morphia/mapping/codec/pojo/EntityModel.java b/core/src/main/java/dev/morphia/mapping/codec/pojo/EntityModel.java
index ab5a48fb502..3c1efe86fb3 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/pojo/EntityModel.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/pojo/EntityModel.java
@@ -28,6 +28,7 @@
 import dev.morphia.mapping.InstanceCreatorFactory;
 import dev.morphia.mapping.InstanceCreatorFactoryImpl;
 import dev.morphia.mapping.MappingException;
+import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.MorphiaInstanceCreator;
 import dev.morphia.mapping.lifecycle.EntityListenerAdapter;
 import dev.morphia.mapping.lifecycle.OnEntityListenerAdapter;
@@ -284,10 +285,11 @@ public PropertyModel getIdProperty() {
     }
 
     /**
+     * @param conversions the Conversions instance to use
      * @return a new InstanceCreator instance for the ClassModel
      */
-    public MorphiaInstanceCreator getInstanceCreator() {
-        return creatorFactory.create();
+    public MorphiaInstanceCreator getInstanceCreator(Conversions conversions) {
+        return creatorFactory.create(conversions);
     }
 
     /**
diff --git a/core/src/main/java/dev/morphia/mapping/codec/pojo/LifecycleDecoder.java b/core/src/main/java/dev/morphia/mapping/codec/pojo/LifecycleDecoder.java
index 683b51c5b98..b2a42921397 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/pojo/LifecycleDecoder.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/pojo/LifecycleDecoder.java
@@ -48,10 +48,12 @@ public T decode(BsonReader reader, DecoderContext decoderContext) {
                 }
             }
         }
-        final MorphiaInstanceCreator instanceCreator = model.getInstanceCreator();
+        final MorphiaInstanceCreator instanceCreator = model.getInstanceCreator(getMorphiaCodec().getConversions());
         T entity = (T) instanceCreator.getInstance();
+
         model.callLifecycleMethods(PreLoad.class, entity, document, getMorphiaCodec().getDatastore());
-        decodeProperties(new DocumentReader(document), decoderContext, instanceCreator, model);
+        decodeProperties(new DocumentReader(document, getMorphiaCodec().getConversions()), decoderContext, instanceCreator,
+                model);
         model.callLifecycleMethods(PostLoad.class, entity, document, getMorphiaCodec().getDatastore());
 
         return entity;
diff --git a/core/src/main/java/dev/morphia/mapping/codec/pojo/MorphiaCodec.java b/core/src/main/java/dev/morphia/mapping/codec/pojo/MorphiaCodec.java
index 63e0a0a35cf..99feb6ed037 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/pojo/MorphiaCodec.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/pojo/MorphiaCodec.java
@@ -7,6 +7,7 @@
 import dev.morphia.mapping.DiscriminatorLookup;
 import dev.morphia.mapping.Mapper;
 import dev.morphia.mapping.MappingException;
+import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.PropertyCodecRegistryImpl;
 import dev.morphia.sofia.Sofia;
 
@@ -24,7 +25,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import static dev.morphia.mapping.codec.Conversions.convert;
 import static org.bson.codecs.configuration.CodecRegistries.fromCodecs;
 import static org.bson.codecs.configuration.CodecRegistries.fromRegistries;
 
@@ -45,6 +45,7 @@ public class MorphiaCodec<T> implements CollectibleCodec<T> {
     private final CodecRegistry registry;
     private final PropertyCodecRegistry propertyCodecRegistry;
     private final DiscriminatorLookup discriminatorLookup;
+    private final Conversions conversions;
     private EntityEncoder<T> encoder;
     private EntityDecoder<T> decoder;
     private Datastore datastore;
@@ -60,9 +61,11 @@ public class MorphiaCodec<T> implements CollectibleCodec<T> {
      */
     public MorphiaCodec(Datastore datastore, EntityModel model,
             List<PropertyCodecProvider> propertyCodecProviders,
-            DiscriminatorLookup discriminatorLookup, CodecRegistry registry) {
+            DiscriminatorLookup discriminatorLookup, CodecRegistry registry,
+            Conversions conversions) {
         this.datastore = datastore;
         this.discriminatorLookup = discriminatorLookup;
+        this.conversions = conversions;
 
         this.entityModel = model;
         this.registry = fromRegistries(fromCodecs(this), registry);
@@ -91,7 +94,7 @@ public Object generateIdIfAbsentFromDocument(Object entity) {
         if (!documentHasId(entity)) {
             if (idProperty != null) {
                 if (ObjectId.class.equals(idProperty.getType()) || String.class.equals(idProperty.getType())) {
-                    idProperty.setValue(entity, convert(new ObjectId(), idProperty.getType()));
+                    idProperty.setValue(entity, conversions.convert(new ObjectId(), idProperty.getType()));
                 } else {
                     LOG.warn(Sofia.noIdAndNotObjectId(entity.getClass().getName()));
                 }
@@ -113,6 +116,13 @@ public BsonValue getDocumentId(Object document) {
         throw new UnsupportedOperationException();
     }
 
+    /**
+     * @return the Conversions instance
+     */
+    public Conversions getConversions() {
+        return conversions;
+    }
+
     /**
      * @return the datastore
      * @since 2.3
diff --git a/core/src/main/java/dev/morphia/mapping/codec/pojo/PropertyModel.java b/core/src/main/java/dev/morphia/mapping/codec/pojo/PropertyModel.java
index f52fa966bbe..96ff9cf7dbf 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/pojo/PropertyModel.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/pojo/PropertyModel.java
@@ -70,11 +70,13 @@ public final class PropertyModel {
     private final Map<Class<? extends Annotation>, Annotation> annotationMap = new HashMap<>();
     private final List<String> loadNames; // List of stored names in order of trying, contains nameToStore and potential aliases
     private final EntityModel entityModel;
+    private final Conversions conversions;
     private Codec<? super Object> codec;
     private Class<?> normalizedType;
 
     PropertyModel(PropertyModelBuilder builder) {
         entityModel = builder.owner();
+        conversions = builder.conversions();
         name = Objects.requireNonNull(builder.name(), Sofia.notNull("name"));
         mappedName = Objects.requireNonNull(builder.mappedName(), Sofia.notNull("name"));
         typeData = Objects.requireNonNull(builder.typeData(), Sofia.notNull("typeData"));
@@ -97,6 +99,7 @@ public final class PropertyModel {
 
     public PropertyModel(EntityModel owner, PropertyModel other) {
         entityModel = owner;
+        conversions = other.conversions;
 
         name = other.name;
         typeData = other.typeData;
@@ -362,7 +365,7 @@ public boolean isTransient() {
      * @param value    the value to set
      */
     public void setValue(Object instance, @Nullable Object value) {
-        accessor.set(instance, Conversions.convert(value, getType()));
+        accessor.set(instance, conversions.convert(value, getType()));
     }
 
     /**
diff --git a/core/src/main/java/dev/morphia/mapping/codec/pojo/PropertyModelBuilder.java b/core/src/main/java/dev/morphia/mapping/codec/pojo/PropertyModelBuilder.java
index 93df8138e98..06539d52c98 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/pojo/PropertyModelBuilder.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/pojo/PropertyModelBuilder.java
@@ -30,6 +30,7 @@
 import dev.morphia.annotations.internal.MorphiaInternal;
 import dev.morphia.config.MorphiaConfig;
 import dev.morphia.mapping.Mapper;
+import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.MorphiaPropertySerialization;
 
 import org.bson.codecs.pojo.PropertyAccessor;
@@ -311,6 +312,13 @@ public String toString() {
                 .toString();
     }
 
+    /**
+     * @return the Conversions instance from the mapper
+     */
+    Conversions conversions() {
+        return mapper.getConversions();
+    }
+
     /**
      * @return the type data
      */
diff --git a/core/src/main/java/dev/morphia/mapping/codec/reader/DocumentReader.java b/core/src/main/java/dev/morphia/mapping/codec/reader/DocumentReader.java
index 58546d21f80..6509dbf5b71 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/reader/DocumentReader.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/reader/DocumentReader.java
@@ -48,16 +48,19 @@ public BsonType get(Class<?> type) {
         }
     };
     private final ReaderState start;
+    private final Conversions conversions;
     private ReaderState current;
 
     /**
      * Construct a new instance.
      *
-     * @param document the document to read from
+     * @param document    the document to read from
+     * @param conversions the Conversions instance to use
      */
-    public DocumentReader(Document document) {
+    public DocumentReader(Document document, Conversions conversions) {
         current = new DocumentState(this, document);
         start = current;
+        this.conversions = conversions;
     }
 
     /**
@@ -147,7 +150,7 @@ public BsonType readBsonType() {
 
     @Override
     public long readDateTime() {
-        Long value = Conversions.convert(stage().value(), long.class);
+        Long value = conversions.convert(stage().value(), long.class);
         if (value != null) {
             return value;
         }
diff --git a/core/src/main/java/dev/morphia/mapping/codec/references/ReferenceCodec.java b/core/src/main/java/dev/morphia/mapping/codec/references/ReferenceCodec.java
index 43263c299e2..e50feaad324 100644
--- a/core/src/main/java/dev/morphia/mapping/codec/references/ReferenceCodec.java
+++ b/core/src/main/java/dev/morphia/mapping/codec/references/ReferenceCodec.java
@@ -24,7 +24,6 @@
 import dev.morphia.mapping.Mapper;
 import dev.morphia.mapping.MappingException;
 import dev.morphia.mapping.codec.BaseReferenceCodec;
-import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.pojo.EntityModel;
 import dev.morphia.mapping.codec.pojo.PropertyHandler;
 import dev.morphia.mapping.codec.pojo.PropertyModel;
@@ -164,7 +163,7 @@ public static Object processId(Datastore datastore, Object decode, DecoderContex
                 try {
                     id = datastore.getCodecRegistry()
                             .get(datastore.getMapper().getClass(document))
-                            .decode(new DocumentReader(document), decoderContext);
+                            .decode(new DocumentReader(document, datastore.getMapper().getConversions()), decoderContext);
                 } catch (CodecConfigurationException e) {
                     throw new MappingException(Sofia.cannotFindTypeInDocument(), e);
                 }
@@ -176,7 +175,7 @@ public static Object processId(Datastore datastore, Object decode, DecoderContex
             if (refId instanceof Document) {
                 refId = datastore.getCodecRegistry()
                         .get(Object.class)
-                        .decode(new DocumentReader((Document) refId), decoderContext);
+                        .decode(new DocumentReader((Document) refId, datastore.getMapper().getConversions()), decoderContext);
             }
             id = new DBRef(ref.getDatabaseName(), ref.getCollectionName(), refId);
         }
@@ -344,7 +343,7 @@ private <T> Class<T> makeProxy() {
                 .intercept(InvocationHandlerAdapter.toField(FIELD_INVOCATION_HANDLER))
                 .defineField(FIELD_INVOCATION_HANDLER, InvocationHandler.class, Visibility.PRIVATE)
                 .make()
-                .load(Thread.currentThread().getContextClassLoader(), Default.WRAPPER)
+                .load(mapper.getClassLoader(), Default.WRAPPER)
                 .getLoaded();
     }
 
@@ -374,13 +373,13 @@ private List<?> mapToEntitiesIfNecessary(List<?> value) {
         Codec<?> codec = getDatastore().getCodecRegistry().get(getEntityModelForField().getType());
         return value.stream()
                 .filter(v -> v instanceof Document && ((Document) v).containsKey("_id"))
-                .map(d -> codec.decode(new DocumentReader((Document) d), DecoderContext.builder().build()))
+                .map(d -> codec.decode(new DocumentReader((Document) d, mapper.getConversions()), DecoderContext.builder().build()))
                 .collect(Collectors.toList());
     }
 
     MorphiaReference<?> readDocument(Document value) {
         final Object id = getDatastore().getCodecRegistry().get(Object.class)
-                .decode(new DocumentReader(value), DecoderContext.builder().build());
+                .decode(new DocumentReader(value, mapper.getConversions()), DecoderContext.builder().build());
         return readSingle(id);
     }
 
@@ -395,7 +394,7 @@ MorphiaReference<?> readMap(Map<Object, Object> value) {
         final Map<Object, Object> ids = new LinkedHashMap<>();
         Class<?> keyType = getTypeData().getTypeParameters().get(0).getType();
         for (Entry<Object, Object> entry : value.entrySet()) {
-            ids.put(Conversions.convert(entry.getKey(), keyType), entry.getValue());
+            ids.put(mapper.getConversions().convert(entry.getKey(), keyType), entry.getValue());
         }
 
         return new MapReference(datastore, ids, getEntityModelForField());
diff --git a/core/src/main/java/dev/morphia/mapping/conventions/FieldDiscovery.java b/core/src/main/java/dev/morphia/mapping/conventions/FieldDiscovery.java
index 5ca5db02c61..6eac4989514 100644
--- a/core/src/main/java/dev/morphia/mapping/conventions/FieldDiscovery.java
+++ b/core/src/main/java/dev/morphia/mapping/conventions/FieldDiscovery.java
@@ -10,6 +10,7 @@
 import dev.morphia.mapping.Mapper;
 import dev.morphia.mapping.MappingException;
 import dev.morphia.mapping.codec.ArrayFieldAccessor;
+import dev.morphia.mapping.codec.Conversions;
 import dev.morphia.mapping.codec.FieldAccessor;
 import dev.morphia.mapping.codec.pojo.EntityModelBuilder;
 import dev.morphia.mapping.codec.pojo.TypeData;
@@ -35,7 +36,7 @@ public void apply(Mapper mapper, EntityModelBuilder builder) {
                                 .name(field.getName())
                                 .typeData(typeData)
                                 .annotations(List.of(field.getDeclaredAnnotations()))
-                                .accessor(getAccessor(getTargetField(builder, field), typeData))
+                                .accessor(getAccessor(getTargetField(builder, field), typeData, mapper.getConversions()))
                                 .modifiers(field.getModifiers())
                                 .discoverMappedName();
                     } catch (NoSuchFieldException e) {
@@ -55,9 +56,9 @@ private Field getTargetField(EntityModelBuilder builder, @NonNull Field field) t
         return builder.targetType().getDeclaredField(field.getName());
     }
 
-    private PropertyAccessor<? super Object> getAccessor(Field field, TypeData<?> typeData) {
+    private PropertyAccessor<? super Object> getAccessor(Field field, TypeData<?> typeData, Conversions conversions) {
         return field.getType().isArray() && !field.getType().getComponentType().equals(byte.class)
-                ? new ArrayFieldAccessor(typeData, field)
+                ? new ArrayFieldAccessor(typeData, field, conversions)
                 : new FieldAccessor(field);
     }
 }
diff --git a/core/src/main/java/dev/morphia/mapping/internal/ConstructorCreator.java b/core/src/main/java/dev/morphia/mapping/internal/ConstructorCreator.java
index 9edb1d76595..85b90027220 100644
--- a/core/src/main/java/dev/morphia/mapping/internal/ConstructorCreator.java
+++ b/core/src/main/java/dev/morphia/mapping/internal/ConstructorCreator.java
@@ -50,9 +50,10 @@ public class ConstructorCreator implements MorphiaInstanceCreator {
     /**
      * @param model       the model
      * @param constructor the constructor to use
+     * @param conversions the Conversions instance to use
      */
     @SuppressFBWarnings("EI_EXPOSE_REP2")
-    public ConstructorCreator(EntityModel model, Constructor<?> constructor) {
+    public ConstructorCreator(EntityModel model, Constructor<?> constructor, Conversions conversions) {
         this.model = model;
         this.constructor = constructor;
         this.constructor.setAccessible(true);
@@ -68,7 +69,7 @@ public ConstructorCreator(EntityModel model, Constructor<?> constructor) {
                 throw new MappingException(Sofia.unnamedConstructorParameter(model.getType().getName()));
             }
             BiFunction<Object[], Object, Void> old = positions.put(name, (Object[] params, Object v) -> {
-                params[finalI] = Conversions.convert(v, parameter.getType());
+                params[finalI] = conversions.convert(v, parameter.getType());
                 return null;
             });
 
diff --git a/core/src/main/java/dev/morphia/query/internal/MorphiaKeyCursor.java b/core/src/main/java/dev/morphia/query/internal/MorphiaKeyCursor.java
index 0026b96d641..1d0d0cee3b9 100644
--- a/core/src/main/java/dev/morphia/query/internal/MorphiaKeyCursor.java
+++ b/core/src/main/java/dev/morphia/query/internal/MorphiaKeyCursor.java
@@ -117,7 +117,7 @@ private <I> I fromDocument(Class<I> type, Document document) {
             aClass = mapper.getClass(document);
         }
 
-        DocumentReader reader = new DocumentReader(document);
+        DocumentReader reader = new DocumentReader(document, datastore.getMapper().getConversions());
 
         return datastore.getCodecRegistry()
                 .get(aClass)
diff --git a/core/src/test/java/dev/morphia/test/TemplatedTestBase.java b/core/src/test/java/dev/morphia/test/TemplatedTestBase.java
index 566dd1beaa5..452f849fd92 100644
--- a/core/src/test/java/dev/morphia/test/TemplatedTestBase.java
+++ b/core/src/test/java/dev/morphia/test/TemplatedTestBase.java
@@ -221,7 +221,7 @@ private <D> List<D> map(Class<D> entityClass, List<Document> documents) {
 
         DecoderContext context = DecoderContext.builder().build();
         return documents.stream()
-                .map(document -> codec.decode(new DocumentReader(document), context))
+                .map(document -> (D) codec.decode(new DocumentReader(document, getMapper().getConversions()), context))
                 .collect(toList());
     }
 }
diff --git a/core/src/test/java/dev/morphia/test/TestBase.java b/core/src/test/java/dev/morphia/test/TestBase.java
index 39c81482fef..db51c8c7c08 100644
--- a/core/src/test/java/dev/morphia/test/TestBase.java
+++ b/core/src/test/java/dev/morphia/test/TestBase.java
@@ -192,7 +192,7 @@ protected <T> T fromDocument(Class<T> type, Document document) {
             aClass = mapper.getClass(document);
         }
 
-        DocumentReader reader = new DocumentReader(document);
+        DocumentReader reader = new DocumentReader(document, mapper.getConversions());
 
         return getDs().getCodecRegistry()
                 .get(aClass)
diff --git a/core/src/test/java/dev/morphia/test/mapping/codec/DocumentReaderTest.java b/core/src/test/java/dev/morphia/test/mapping/codec/DocumentReaderTest.java
index 1f8bd52773b..48547211428 100644
--- a/core/src/test/java/dev/morphia/test/mapping/codec/DocumentReaderTest.java
+++ b/core/src/test/java/dev/morphia/test/mapping/codec/DocumentReaderTest.java
@@ -93,7 +93,7 @@ public void nestedDatabaseRead() {
         Document first = collection.find().first();
 
         Parent decode = getDs().getCodecRegistry().get(Parent.class)
-                .decode(new DocumentReader(first), DecoderContext.builder().build());
+                .decode(new DocumentReader(first, getMapper().getConversions()), DecoderContext.builder().build());
 
         assertEquals(parent, decode);
     }
@@ -280,7 +280,7 @@ private void readDocument(int count) {
     }
 
     private void setup(Document document) {
-        reader = new DocumentReader(document);
+        reader = new DocumentReader(document, getMapper().getConversions());
     }
 
     private void step(Consumer<BsonReader> function) {
diff --git a/docs/modules/ROOT/examples/complete-morphia-config.properties b/docs/modules/ROOT/examples/complete-morphia-config.properties
index 4b6fcc9e971..2172fbdec20 100644
--- a/docs/modules/ROOT/examples/complete-morphia-config.properties
+++ b/docs/modules/ROOT/examples/complete-morphia-config.properties
@@ -15,6 +15,10 @@ morphia.apply-indexes=false
 ######
 morphia.auto-import-models=false
 ######
+# Required
+######
+morphia.class-loader=jdk.internal.loader.ClassLoaders$AppClassLoader
+######
 # Optional
 ######
 morphia.codec-provider=
diff --git a/docs/modules/ROOT/examples/legacy-morphia-config.properties b/docs/modules/ROOT/examples/legacy-morphia-config.properties
index 54bb6cdf4b8..a7edcad3d54 100644
--- a/docs/modules/ROOT/examples/legacy-morphia-config.properties
+++ b/docs/modules/ROOT/examples/legacy-morphia-config.properties
@@ -3,6 +3,10 @@
 ######
 morphia.auto-import-models=false
 ######
+# Required
+######
+morphia.class-loader=jdk.internal.loader.ClassLoaders$AppClassLoader
+######
 # default=camelCase
 # possible values=camelCase, identity, kebabCase, lowerCase, snakeCase, fqcn
 ######
diff --git a/docs/modules/ROOT/examples/minimal-morphia-config.properties b/docs/modules/ROOT/examples/minimal-morphia-config.properties
index c7c75f1aab2..afc46e46e20 100644
--- a/docs/modules/ROOT/examples/minimal-morphia-config.properties
+++ b/docs/modules/ROOT/examples/minimal-morphia-config.properties
@@ -1,4 +1,8 @@
 ######
 # default=true
 ######
-morphia.auto-import-models=false
\ No newline at end of file
+morphia.auto-import-models=false
+######
+# Required
+######
+morphia.class-loader=jdk.internal.loader.ClassLoaders$AppClassLoader
\ No newline at end of file