diff --git a/game_engine_save_as_runtime.py b/game_engine_save_as_runtime.py
index f600bd5de41d81688901016b8a13d49b3e5717ea..369169023c045ccf397f27ed47c418e324cd60b2 100644
--- a/game_engine_save_as_runtime.py
+++ b/game_engine_save_as_runtime.py
@@ -201,9 +201,8 @@ class SaveAsRuntime(bpy.types.Operator):
 
 
 def menu_func(self, context):
-
     ext = '.app' if sys.platform == 'darwin' else os.path.splitext(bpy.app.binary_path)[-1]
-    default_blend_path = bpy.data.filepath.replace(".blend", ext)
+    default_blend_path = bpy.path.ensure_ext(bpy.data.filepath, ext)
     self.layout.operator(SaveAsRuntime.bl_idname, text=SaveAsRuntime.bl_label).filepath = default_blend_path