diff --git a/Tests/test_imageqt.py b/Tests/test_imageqt.py
index 7d56ce5f101..c7a73d41b33 100644
--- a/Tests/test_imageqt.py
+++ b/Tests/test_imageqt.py
@@ -55,12 +55,7 @@ def test_closed_file() -> None:
         ImageQt.ImageQt("Tests/images/hopper.gif")
 
 
-def test_deprecated_align8to32_matches_new_impl() -> None:
-    im = hopper("P").resize((113, 113))  # size causes alignment issues
-    w, h = im.size
-    with pytest.warns(DeprecationWarning, match="Implement"):
-        old_b = ImageQt.align8to32(im.tobytes(), w, im.mode)
-    stride = ImageQt._aligned_stride(w, im.mode)
-    new_b = im.tobytes("raw", im.mode, stride)
-    assert old_b == new_b
-    assert len(old_b) == stride * h
+def test_align8to32_deprecation() -> None:
+    im = hopper("1")
+    with pytest.warns(DeprecationWarning, match="ImageQt.align8to32"):
+        ImageQt.align8to32(im.tobytes(), im.width, im.mode)
diff --git a/docs/deprecations.rst b/docs/deprecations.rst
index 70745104483..2d56df15da8 100644
--- a/docs/deprecations.rst
+++ b/docs/deprecations.rst
@@ -21,7 +21,7 @@ ExifTags.IFD.Makernote
 ``ExifTags.IFD.MakerNote``.
 
 Image getdata()
-~~~~~~~~~~~~~~~
+^^^^^^^^^^^^^^^
 
 .. deprecated:: 12.1.0
 
@@ -30,6 +30,14 @@ Image getdata()
 identical, except that it returns a tuple of pixel values, instead of an internal
 Pillow data type.
 
+ImageQt align8to32()
+^^^^^^^^^^^^^^^^^^^^
+
+.. deprecated:: 13.0.0
+
+``ImageQt.align8to32()`` has been deprecated. This was an undocumented helper function
+intended for internal use, so there is no replacement.
+
 Removed features
 ----------------
 
diff --git a/docs/releasenotes/13.0.0.rst b/docs/releasenotes/13.0.0.rst
index d6d0ff6c40e..5ccec3b1e30 100644
--- a/docs/releasenotes/13.0.0.rst
+++ b/docs/releasenotes/13.0.0.rst
@@ -69,10 +69,11 @@ ImageCms.ImageCmsProfile.product_name and .product_info
 Deprecations
 ============
 
-TODO
-^^^^
+ImageQt align8to32()
+^^^^^^^^^^^^^^^^^^^^
 
-TODO
+``ImageQt.align8to32()`` has been deprecated. This was an undocumented helper function
+intended for internal use, so there is no replacement.
 
 API changes
 ===========
diff --git a/src/PIL/ImageQt.py b/src/PIL/ImageQt.py
index ed747ffefa7..c5d09f00d84 100644
--- a/src/PIL/ImageQt.py
+++ b/src/PIL/ImageQt.py
@@ -108,9 +108,7 @@ def align8to32(bytes: bytes, width: int, mode: str) -> bytes:
     """
     converts each scanline of data from 8 bit to 32 bit aligned
     """
-    deprecate(
-        "ImageQt.align8to32", 14, action="Implement a similar function in your code"
-    )
+    deprecate("ImageQt.align8to32", 14)
 
     bits_per_pixel = {"1": 1, "L": 8, "P": 8, "I;16": 16}[mode]
 
@@ -133,14 +131,6 @@ def align8to32(bytes: bytes, width: int, mode: str) -> bytes:
     return b"".join(new_data)
 
 
-def _aligned_stride(width: int, mode: str) -> int:
-    # Compute the stride (scanline size) in bytes when aligned
-    # to Qt's requirement that scanlines be aligned to 4 bytes.
-    mode_bpp = {"1": 1, "L": 8, "P": 8, "I;16": 16}
-    bytes_per_line = (mode_bpp[mode] * width + 7) // 8
-    return (bytes_per_line + 3) & ~3
-
-
 def _toqclass_helper(im: Image.Image | str | QByteArray) -> dict[str, Any]:
     data = None
     colortable = None
@@ -187,7 +177,12 @@ def _toqclass_helper(im: Image.Image | str | QByteArray) -> dict[str, Any]:
 
     size = im.size
     if data is None:
-        data = im.tobytes("raw", im.mode, _aligned_stride(size[0], im.mode))
+        # Compute the stride (scanline size) in bytes when aligned
+        # to Qt's requirement that scanlines be aligned to 32 bits.
+        bpp = {"1": 1, "L": 8, "P": 8, "I;16": 16}[im.mode]
+        stride = (bpp * size[0] + 31) // 32 * (32 // 8)
+
+        data = im.tobytes("raw", im.mode, stride)
     if exclusive_fp:
         im.close()
     return {"data": data, "size": size, "format": format, "colortable": colortable}