diff --git a/ultralytics/engine/predictor.py b/ultralytics/engine/predictor.py
index 01ef615861..921f273f68 100644
--- a/ultralytics/engine/predictor.py
+++ b/ultralytics/engine/predictor.py
@@ -151,7 +151,7 @@ class BasePredictor:
         Returns:
             (list): A list of transformed images.
         """
-        same_shapes = all(x.shape == im[0].shape for x in im)
+        same_shapes = len({x.shape for x in im}) == 1
         letterbox = LetterBox(self.imgsz, auto=same_shapes and self.model.pt, stride=self.model.stride)
         return [letterbox(image=x) for x in im]