diff --git a/timm_image.py b/timm_image.py
index b0188a7..98bf302 100644
--- a/timm_image.py
+++ b/timm_image.py
@@ -83,7 +83,7 @@ class TimmImage(NNOperator):
             imgs = data
         img_list = []
         for img in imgs:
-            img = self.convert_img(img) if isinstance(img, numpy.ndarray) else img
+            img = self.convert_img(img) if isinstance(img, numpy.ndarray) else img.convert('RGB')
             img = img if self.skip_tfms else self.tfms(img)
             img_list.append(img)
         inputs = torch.stack(img_list)