diff --git a/Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs b/Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs
index 635e1e0d2..27501679c 100644
--- a/Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs
+++ b/Assets/UniGLTF/Runtime/Extensions/StringExtensions.cs
@@ -70,6 +70,10 @@ namespace UniGLTF
             {
                 path = path.Replace(x, '+');
             }
+
+            if (path.StartsWith('.'))
+                path = '+' + path;
+
             return path;
         }
 
diff --git a/Assets/VRM10/Runtime/StringExtensions.cs b/Assets/VRM10/Runtime/StringExtensions.cs
index efa180350..f5fd9f8bd 100644
--- a/Assets/VRM10/Runtime/StringExtensions.cs
+++ b/Assets/VRM10/Runtime/StringExtensions.cs
@@ -67,6 +67,8 @@ namespace UniVRM10
             {
                 path = path.Replace(x, '+');
             }
+            if (path.StartsWith('.'))
+                path = '+' + path;
             return path;
         }
     }