diff --git a/Tests/images/apng/dispose_op_background_p_mode.png b/Tests/images/apng/dispose_op_background_p_mode.png
new file mode 100644
index 00000000000..e5fb4784d26
Binary files /dev/null and b/Tests/images/apng/dispose_op_background_p_mode.png differ
diff --git a/Tests/test_file_apng.py b/Tests/test_file_apng.py
index 1fd7d8c3d22..0eca786900a 100644
--- a/Tests/test_file_apng.py
+++ b/Tests/test_file_apng.py
@@ -104,6 +104,13 @@ def test_apng_dispose_region():
         assert im.getpixel((64, 32)) == (0, 255, 0, 255)
 
 
+def test_apng_dispose_op_background_p_mode():
+    with Image.open("Tests/images/apng/dispose_op_background_p_mode.png") as im:
+        im.seek(1)
+        im.load()
+        assert im.size == (128, 64)
+
+
 def test_apng_blend():
     with Image.open("Tests/images/apng/blend_op_source_solid.png") as im:
         im.seek(im.n_frames - 1)
diff --git a/src/PIL/PngImagePlugin.py b/src/PIL/PngImagePlugin.py
index 2cbc93093cd..e027953dd56 100644
--- a/src/PIL/PngImagePlugin.py
+++ b/src/PIL/PngImagePlugin.py
@@ -904,7 +904,7 @@ def load_end(self):
                 dispose = self._prev_im.copy()
                 dispose = self._crop(dispose, self.dispose_extent)
             elif self.dispose_op == APNG_DISPOSE_OP_BACKGROUND:
-                dispose = Image.core.fill("RGBA", self.size, (0, 0, 0, 0))
+                dispose = Image.core.fill(self.im.mode, self.size)
                 dispose = self._crop(dispose, self.dispose_extent)
             else:
                 dispose = None