diff --git a/core/src/main/java/google/registry/model/translators/VKeyTranslatorFactory.java b/core/src/main/java/google/registry/model/translators/VKeyTranslatorFactory.java
index fd529f2b8..99615f879 100644
--- a/core/src/main/java/google/registry/model/translators/VKeyTranslatorFactory.java
+++ b/core/src/main/java/google/registry/model/translators/VKeyTranslatorFactory.java
@@ -16,15 +16,16 @@ package google.registry.model.translators;
 
 import static com.google.common.base.Functions.identity;
 import static com.google.common.base.Preconditions.checkArgument;
-import static com.google.common.collect.ImmutableMap.toImmutableMap;
 import static google.registry.model.EntityClasses.ALL_CLASSES;
 
 import com.google.appengine.api.datastore.Key;
-import com.google.common.collect.ImmutableMap;
+import com.google.common.annotations.VisibleForTesting;
 import com.googlecode.objectify.annotation.EntitySubclass;
 import google.registry.persistence.VKey;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 
 /**
@@ -39,10 +40,10 @@ public class VKeyTranslatorFactory extends AbstractSimpleTranslatorFactory<VKey,
   // name, which is all the datastore key gives us.
   // Note that entities annotated with @EntitySubclass are removed because they share the same
   // kind of the key with their parent class.
-  private static final ImmutableMap<String, Class<?>> CLASS_REGISTRY =
+  private static final Map<String, Class<?>> CLASS_REGISTRY =
       ALL_CLASSES.stream()
           .filter(clazz -> !clazz.isAnnotationPresent(EntitySubclass.class))
-          .collect(toImmutableMap(com.googlecode.objectify.Key::getKind, identity()));
+          .collect(Collectors.toMap(com.googlecode.objectify.Key::getKind, identity()));
 
   public VKeyTranslatorFactory() {
     super(VKey.class);
@@ -59,6 +60,7 @@ public class VKeyTranslatorFactory extends AbstractSimpleTranslatorFactory<VKey,
 
   /** Create a VKey from an objectify Key. */
   @Nullable
+  @SuppressWarnings("unchecked")
   public static <T> VKey<T> createVKey(@Nullable com.googlecode.objectify.Key<T> key) {
     if (key == null) {
       return null;
@@ -95,6 +97,11 @@ public class VKeyTranslatorFactory extends AbstractSimpleTranslatorFactory<VKey,
     return createVKey(com.googlecode.objectify.Key.create(urlSafe));
   }
 
+  @VisibleForTesting
+  public static void addTestEntityClass(Class<?> clazz) {
+    CLASS_REGISTRY.put(com.googlecode.objectify.Key.getKind(clazz), clazz);
+  }
+
   @Override
   public SimpleTranslator<VKey, Key> createTranslator() {
     return new SimpleTranslator<VKey, Key>() {
diff --git a/core/src/test/java/google/registry/model/translators/VKeyTranslatorFactoryTest.java b/core/src/test/java/google/registry/model/translators/VKeyTranslatorFactoryTest.java
index 4f9df0c5d..15cdaea1e 100644
--- a/core/src/test/java/google/registry/model/translators/VKeyTranslatorFactoryTest.java
+++ b/core/src/test/java/google/registry/model/translators/VKeyTranslatorFactoryTest.java
@@ -27,16 +27,24 @@ import google.registry.model.ofy.CommitLogCheckpointRoot;
 import google.registry.model.reporting.HistoryEntry;
 import google.registry.persistence.VKey;
 import google.registry.testing.AppEngineExtension;
+import google.registry.testing.TestObject;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
 
 public class VKeyTranslatorFactoryTest {
 
   @RegisterExtension
-  public final AppEngineExtension appEngine = AppEngineExtension.builder().withDatastore().build();
+  public final AppEngineExtension appEngine =
+      AppEngineExtension.builder().withDatastore().withOfyTestEntities(TestObject.class).build();
 
   VKeyTranslatorFactoryTest() {}
 
+  @BeforeAll
+  static void beforeAll() {
+    VKeyTranslatorFactory.addTestEntityClass(TestObject.class);
+  }
+
   @Test
   void testEntityWithFlatKey() {
     // Creating an objectify key instead of a datastore key as this should get a correctly formatted
@@ -88,4 +96,11 @@ public class VKeyTranslatorFactoryTest {
     assertThat(vkey.getOfyKey()).isEqualTo(key);
     assertThat(vkey.getSqlKey()).isEqualTo("ROID-1");
   }
+
+  @Test
+  void testExtraEntityClass() {
+    TestObject testObject = TestObject.create("id", "field");
+    Key<TestObject> key = Key.create(testObject);
+    assertThat(VKeyTranslatorFactory.createVKey(key).getSqlKey()).isEqualTo("id");
+  }
 }
diff --git a/core/src/test/java/google/registry/testing/TestObject.java b/core/src/test/java/google/registry/testing/TestObject.java
index 7392ccf9a..15b2e368f 100644
--- a/core/src/test/java/google/registry/testing/TestObject.java
+++ b/core/src/test/java/google/registry/testing/TestObject.java
@@ -23,6 +23,7 @@ import com.googlecode.objectify.annotation.Parent;
 import google.registry.model.ImmutableObject;
 import google.registry.model.annotations.VirtualEntity;
 import google.registry.model.common.EntityGroupRoot;
+import google.registry.persistence.VKey;
 import google.registry.schema.replay.EntityTest.EntityForTesting;
 
 /** A test model object that can be persisted in any entity group. */
@@ -30,11 +31,9 @@ import google.registry.schema.replay.EntityTest.EntityForTesting;
 @EntityForTesting
 public class TestObject extends ImmutableObject {
 
-  @Parent
-  Key<EntityGroupRoot> parent;
+  @Parent Key<EntityGroupRoot> parent;
 
-  @Id
-  String id;
+  @Id String id;
 
   String field;
 
@@ -46,6 +45,10 @@ public class TestObject extends ImmutableObject {
     return field;
   }
 
+  public static VKey<TestObject> createVKey(Key<TestObject> key) {
+    return VKey.create(TestObject.class, key.getName(), key);
+  }
+
   public static TestObject create(String id) {
     return create(id, null);
   }
@@ -68,8 +71,7 @@ public class TestObject extends ImmutableObject {
   @EntityForTesting
   public static class TestVirtualObject extends ImmutableObject {
 
-    @Id
-    String id;
+    @Id String id;
 
     /**
      * Expose a factory method for testing saves of virtual entities; in real life this would never