diff --git a/src/api/java/de/teamlapen/vampirism/api/entity/IVampirismEntityRegistry.java b/src/api/java/de/teamlapen/vampirism/api/entity/IVampirismEntityRegistry.java
index f6a309a27b..236bdd26c7 100755
--- a/src/api/java/de/teamlapen/vampirism/api/entity/IVampirismEntityRegistry.java
+++ b/src/api/java/de/teamlapen/vampirism/api/entity/IVampirismEntityRegistry.java
@@ -22,7 +22,9 @@ public interface IVampirismEntityRegistry {
      * Requires a blood value to be registered for that creature
      *
      * @param overlay_loc Location of the overlay texture file
+     * @deprecated use data driven system
      */
+    @Deprecated
     @ThreadSafeAPI
     void addConvertible(EntityType<? extends PathfinderMob> type, ResourceLocation overlay_loc);
 
@@ -32,7 +34,10 @@ public interface IVampirismEntityRegistry {
      *
      * @param helper      Helper instance for the DefaultHandler to specify some values for the converted creature
      * @param overlay_loc Location of the overlay texture file
+     *
+     * @deprecated use data driven system
      */
+    @Deprecated
     @ThreadSafeAPI
     void addConvertible(EntityType<? extends PathfinderMob> type, ResourceLocation overlay_loc, IConvertingHandler.IDefaultHelper helper);
 
@@ -42,7 +47,9 @@ public interface IVampirismEntityRegistry {
      *
      * @param overlay_loc Location of the overlay texture file. Only required if Vampirism's default Converted Creature renderer is used, if you handle that stuff yourself, null is just fine.
      * @param handler     Handles the conversion
+     * @deprecated use data driven system
      */
+    @Deprecated
     @ThreadSafeAPI
     void addConvertible(EntityType<? extends PathfinderMob> type, ResourceLocation overlay_loc, IConvertingHandler<?> handler);
 
diff --git a/src/main/java/de/teamlapen/vampirism/entity/converted/VampirismEntityRegistry.java b/src/main/java/de/teamlapen/vampirism/entity/converted/VampirismEntityRegistry.java
index 56e59b1d43..8a8511bd95 100755
--- a/src/main/java/de/teamlapen/vampirism/entity/converted/VampirismEntityRegistry.java
+++ b/src/main/java/de/teamlapen/vampirism/entity/converted/VampirismEntityRegistry.java
@@ -33,6 +33,7 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
@@ -51,9 +52,14 @@ public class VampirismEntityRegistry implements IVampirismEntityRegistry {
      * Used to store convertible handlers after {@link FMLCommonSetupEvent}
      */
     @NotNull
-    private final Map<EntityType<? extends PathfinderMob>, IConvertingHandler<?>> convertibles = new ConcurrentHashMap<>();
+    private final Map<EntityType<? extends PathfinderMob>, IConvertingHandler<?>> convertibles = new HashMap<>();
     @NotNull
-    private final Map<EntityType<? extends PathfinderMob>, ResourceLocation> convertibleOverlay = new ConcurrentHashMap<>();
+    private final Map<EntityType<? extends PathfinderMob>, ResourceLocation> convertibleOverlay = new HashMap<>();
+
+    @NotNull
+    private final Map<EntityType<? extends PathfinderMob>, IConvertingHandler<?>> convertiblesAPI = new ConcurrentHashMap<>();
+    @NotNull
+    private final Map<EntityType<? extends PathfinderMob>, ResourceLocation> convertibleOverlayAPI = new ConcurrentHashMap<>();
     /**
      * Stores custom extended creature constructors after {@link InterModEnqueueEvent}
      */
@@ -85,10 +91,10 @@ public void addConvertible(EntityType<? extends PathfinderMob> type, ResourceLoc
     @ThreadSafeAPI
     public void addConvertible(EntityType<? extends PathfinderMob> type, @Nullable ResourceLocation overlay_loc, @NotNull IConvertingHandler<?> handler) {
         if (finished) throw new IllegalStateException("Register convertibles during InterModEnqueueEvent");
-        convertibles.put(type, handler);
+        convertiblesAPI.put(type, handler);
 
         if (FMLEnvironment.dist.isClient() && overlay_loc != null) {
-            convertibleOverlay.put(type, overlay_loc);
+            convertibleOverlayAPI.put(type, overlay_loc);
         }
     }
 
@@ -183,6 +189,8 @@ public void applyDataConvertibleOverlays(Map<EntityType<? extends PathfinderMob>
     public void applyDataConvertibles(Map<EntityType<? extends PathfinderMob>, ConvertiblesReloadListener.EntityEntry> entries) {
         this.convertibles.clear();
         this.convertibleOverlay.clear();
+        this.convertibles.putAll(this.convertiblesAPI);
+        this.convertibleOverlay.putAll(this.convertibleOverlayAPI);
         entries.forEach((type, entry) -> {
             Optional<IConvertingHandler<?>> handler = entry.converter().map(Converter::createHandler);
             this.convertibles.put(type, handler.orElseGet(() -> new DefaultConverter().createHandler()));