diff --git a/src/PIL/ImageStat.py b/src/PIL/ImageStat.py
index 2cb841eef..8bc504526 100644
--- a/src/PIL/ImageStat.py
+++ b/src/PIL/ImageStat.py
@@ -52,9 +52,9 @@ class Stat:
         """
         if isinstance(image_or_list, Image.Image):
             self.h = image_or_list.histogram(mask)
-        else:
+        elif isinstance(image_or_list, list):
             self.h = image_or_list
-        if not isinstance(self.h, list):
+        else:
             msg = "first argument must be image or list"  # type: ignore[unreachable]
             raise TypeError(msg)
         self.bands = list(range(len(self.h) // 256))