diff --git a/Editor/MergeAnimatorProcessor.cs b/Editor/MergeAnimatorProcessor.cs
index 223cfde7..50efd939 100644
--- a/Editor/MergeAnimatorProcessor.cs
+++ b/Editor/MergeAnimatorProcessor.cs
@@ -236,8 +236,10 @@ namespace nadena.dev.modular_avatar.core.editor
             }
         }
 
-        private bool? ProbeWriteDefaults(AnimatorController controller)
+        internal static bool? ProbeWriteDefaults(AnimatorController controller)
         {
+            if (controller == null) return null;
+            
             bool hasWDOn = false;
             bool hasWDOff = false;
 
diff --git a/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectPass.cs b/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectPass.cs
index b3e49145..793fba66 100644
--- a/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectPass.cs
+++ b/Editor/ReactiveObjects/AnimationGeneration/ReactiveObjectPass.cs
@@ -25,6 +25,7 @@ namespace nadena.dev.modular_avatar.core.editor
         private HashSet<string> activeProps = new();
         
         private AnimationClip _initialStateClip;
+        private bool _writeDefaults;
         
         public ReactiveObjectPass(ndmf.BuildContext context)
         {
@@ -33,6 +34,10 @@ namespace nadena.dev.modular_avatar.core.editor
 
         internal void Execute()
         {
+            // Having a WD OFF layer after WD ON layers can break WD. We match the behavior of the existing states,
+            // and if mixed, use WD ON to maximize compatibility.
+            _writeDefaults = MergeAnimatorProcessor.ProbeWriteDefaults(FindFxController().animatorController as AnimatorController) ?? true;
+            
             var analysis = new ReactiveObjectAnalyzer(context).Analyze(context.AvatarRootObject);
 
             var shapes = analysis.Shapes;
@@ -277,7 +282,7 @@ namespace nadena.dev.modular_avatar.core.editor
             var initial = new AnimationClip();
             var initialState = new AnimatorState();
             initialState.motion = initial;
-            initialState.writeDefaultValues = false;
+            initialState.writeDefaultValues = _writeDefaults;
             initialState.name = "<default>";
             asm.defaultState = initialState;
 
@@ -349,7 +354,7 @@ namespace nadena.dev.modular_avatar.core.editor
                     state.name = group.ControllingConditions[0].DebugName.Replace(".", "_");
 
                     state.motion = clip;
-                    state.writeDefaultValues = false;
+                    state.writeDefaultValues = _writeDefaults;
                     states.Add(new ChildAnimatorState
                     {
                         position = new Vector3(x, y),
@@ -525,13 +530,13 @@ namespace nadena.dev.modular_avatar.core.editor
 
         private void ApplyController(AnimatorStateMachine asm, string layerName)
         {
-            var fx = context.AvatarDescriptor.baseAnimationLayers
-                .FirstOrDefault(l => l.type == VRCAvatarDescriptor.AnimLayerType.FX);
+            var fx = FindFxController();
+            
             if (fx.animatorController == null)
             {
                 throw new InvalidOperationException("No FX layer found");
             }
-
+            
             if (!context.IsTemporaryAsset(fx.animatorController))
             {
                 throw new InvalidOperationException("FX layer is not a temporary asset");
@@ -567,5 +572,13 @@ namespace nadena.dev.modular_avatar.core.editor
                 }
             ).ToArray();
         }
+
+        private VRCAvatarDescriptor.CustomAnimLayer FindFxController()
+        {
+            var fx = context.AvatarDescriptor.baseAnimationLayers
+                .FirstOrDefault(l => l.type == VRCAvatarDescriptor.AnimLayerType.FX);
+
+            return fx;
+        }
     }
 }