@@ -62,6 +62,7 @@ def test_exception_gif_extents(self) -> None:
         with Image.open("Tests/images/decompression_bomb_extents.gif") as im:
             with pytest.raises(Image.DecompressionBombError):
                 im.seek(1)
+            assert im.size == (100, 100)
 
     def test_exception_gif_zero_width(self, monkeypatch: pytest.MonkeyPatch) -> None:
         # Set limit to trigger exception on the test file
 
@@ -286,8 +286,9 @@ def _seek(self, frame: int, update_image: bool = True) -> None:
                 x0, y0 = i16(s, 0), i16(s, 2)
                 x1, y1 = x0 + i16(s, 4), y0 + i16(s, 6)
                 if (x1 > self.size[0] or y1 > self.size[1]) and update_image:
-                    self._size = max(x1, self.size[0]), max(y1, self.size[1])
-                    Image._decompression_bomb_check(self._size)
+                    size = max(x1, self.size[0]), max(y1, self.size[1])
+                    Image._decompression_bomb_check(size)
+                    self._size = size
                 frame_dispose_extent = x0, y0, x1, y1
                 flags = s[8]