diff --git a/timm_image.py b/timm_image.py
index 1e869b9..ab132b4 100644
--- a/timm_image.py
+++ b/timm_image.py
@@ -139,7 +139,7 @@ class TimmImage(NNOperator):
         return config
 
     @arg(1, to_image_color('RGB'))
-    def convert_img(self, img: towhee._types.Image):
+    def convert_img(self, img: 'towhee.types.Image'):
         img = PILImage.fromarray(img.astype('uint8'), 'RGB')
         return img