diff --git a/Tests/test_file_mpo.py b/Tests/test_file_mpo.py
index 1f335985afc..ac802dd0717 100644
--- a/Tests/test_file_mpo.py
+++ b/Tests/test_file_mpo.py
@@ -356,7 +356,7 @@ def test_save_all() -> None:
             assert_image_similar(im, im_reloaded, 30)
 
     im_rgb = Image.new("RGB", (1, 1))
-    for colors in (("#f00",), ("#f00", "#0f0")):
+    for colors in (("#f00",), ("#f00", "#0f0"), ("#f00", "#0f0", "#00f")):
         append_images = [Image.new("RGB", (1, 1), color) for color in colors]
         im_reloaded = roundtrip(im_rgb, save_all=True, append_images=append_images)
 
diff --git a/src/PIL/MpoImagePlugin.py b/src/PIL/MpoImagePlugin.py
index a2c89d9df1e..14d1b901d7a 100644
--- a/src/PIL/MpoImagePlugin.py
+++ b/src/PIL/MpoImagePlugin.py
@@ -51,6 +51,7 @@ def _save_all(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
         return
 
     mpf_offset = 28
+    prev_offset = 0
     offsets: list[int] = []
     im_sequences = [im, *append_images]
     total = sum(getattr(seq, "n_frames", 1) for seq in im_sequences)
@@ -72,12 +73,13 @@ def _save_all(im: Image.Image, fp: IO[bytes], filename: str | bytes) -> None:
                     mpf_offset += 4 + len(exif)
 
                 JpegImagePlugin._save(im_frame, fp, filename)
-                offsets.append(fp.tell())
             else:
                 encoderinfo = im_frame._attach_default_encoderinfo(im)
                 im_frame.save(fp, "JPEG")
                 im_frame.encoderinfo = encoderinfo
-                offsets.append(fp.tell() - offsets[-1])
+            offset = fp.tell()
+            offsets.append(offset - prev_offset)
+            prev_offset = offset
 
     ifd = TiffImagePlugin.ImageFileDirectory_v2()
     ifd[0xB000] = b"0100"