diff --git a/Editor/Inspector/BoneProxyEditor.cs b/Editor/Inspector/BoneProxyEditor.cs
index f9d3ec6d..22566984 100644
--- a/Editor/Inspector/BoneProxyEditor.cs
+++ b/Editor/Inspector/BoneProxyEditor.cs
@@ -95,7 +95,7 @@ namespace nadena.dev.modular_avatar.core.editor
                         var t = (ModularAvatarBoneProxy) targets[i];
                         Undo.RecordObjects(targets, "Set targets");
                         var xform = ((TempObjRef) objRefs[i]).target;
-                        if (RuntimeUtil.FindAvatarTransformInParents(xform)?.gameObject != parentAvatar) continue;
+                        if (xform != null && RuntimeUtil.FindAvatarTransformInParents(xform)?.gameObject != parentAvatar) continue;
                         t.target = xform;
                     }
                 }
@@ -159,4 +159,4 @@ namespace nadena.dev.modular_avatar.core.editor
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/Runtime/ModularAvatarBoneProxy.cs b/Runtime/ModularAvatarBoneProxy.cs
index 35f0cd7d..38957bdc 100644
--- a/Runtime/ModularAvatarBoneProxy.cs
+++ b/Runtime/ModularAvatarBoneProxy.cs
@@ -205,6 +205,13 @@ namespace nadena.dev.modular_avatar.core
 
             Transform iter = newTarget;
 
+            if (newTarget == null)
+            {
+                boneReference = HumanBodyBones.LastBone;
+                subPath = null;
+                return;
+            }
+
             if (newTarget == avatarTransform)
             {
                 boneReference = HumanBodyBones.LastBone;
@@ -230,4 +237,4 @@ namespace nadena.dev.modular_avatar.core
             _targetCache = newTarget;
         }
     }
-}
\ No newline at end of file
+}