diff --git a/ultralytics/engine/predictor.py b/ultralytics/engine/predictor.py
index c28e1895..c5250166 100644
--- a/ultralytics/engine/predictor.py
+++ b/ultralytics/engine/predictor.py
@@ -155,7 +155,7 @@ class BasePredictor:
         same_shapes = len({x.shape for x in im}) == 1
         letterbox = LetterBox(
             self.imgsz,
-            auto=same_shapes and (self.model.pt or getattr(self.model, "dynamic", False)),
+            auto=same_shapes and (self.model.pt or (getattr(self.model, "dynamic", False) and not self.model.imx)),
             stride=self.model.stride,
         )
         return [letterbox(image=x) for x in im]