diff --git a/Tests/test_imagecms.py b/Tests/test_imagecms.py
index 8d463d0eb..55a4a87fb 100644
--- a/Tests/test_imagecms.py
+++ b/Tests/test_imagecms.py
@@ -673,12 +673,6 @@ def test_auxiliary_channels_isolated() -> None:
                 assert_image_equal(test_image.convert(dst_format[2]), reference_image)
 
 
-def test_long_modes() -> None:
-    p = ImageCms.getOpenProfile("Tests/icc/sGrey-v2-nano.icc")
-    with pytest.warns(DeprecationWarning, match="ABCDEFGHI"):
-        ImageCms.buildTransform(p, p, "ABCDEFGHI", "ABCDEFGHI")
-
-
 @pytest.mark.parametrize("mode", ("RGB", "RGBA", "RGBX"))
 def test_rgb_lab(mode: str) -> None:
     im = Image.new(mode, (1, 1))
@@ -696,11 +690,3 @@ def test_cmyk_lab() -> None:
     im = Image.new("CMYK", (1, 1))
     converted_im = im.convert("LAB")
     assert converted_im.getpixel((0, 0)) == (255, 128, 128)
-
-
-def test_deprecation() -> None:
-    profile = ImageCmsProfile(ImageCms.createProfile("sRGB"))
-    with pytest.warns(DeprecationWarning, match="RGBA;16B"):
-        ImageCms.ImageCmsTransform(profile, profile, "RGBA;16B", "RGB")
-    with pytest.warns(DeprecationWarning, match="RGBA;16B"):
-        ImageCms.ImageCmsTransform(profile, profile, "RGB", "RGBA;16B")
diff --git a/docs/deprecations.rst b/docs/deprecations.rst
index 183abea09..772e88147 100644
--- a/docs/deprecations.rst
+++ b/docs/deprecations.rst
@@ -12,15 +12,6 @@ Deprecated features
 Below are features which are considered deprecated. Where appropriate,
 a :py:exc:`DeprecationWarning` is issued.
 
-Non-image modes in ImageCms
-^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-.. deprecated:: 10.4.0
-
-The use in :py:mod:`.ImageCms` of input modes and output modes that are not Pillow
-image modes has been deprecated. Defaulting to "L" or "1" if the mode cannot be mapped
-is also deprecated.
-
 ImageDraw.getdraw hints parameter
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -171,6 +162,16 @@ BGR;15, BGR 16 and BGR;24
 
 The experimental BGR;15, BGR;16 and BGR;24 modes have been removed.
 
+Non-image modes in ImageCms
+^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. deprecated:: 10.4.0
+.. versionremoved:: 12.0.0
+
+The use in :py:mod:`.ImageCms` of input modes and output modes that are not Pillow
+image modes has been removed. Defaulting to "L" or "1" if the mode cannot be mapped has
+also been removed.
+
 Support for LibTIFF earlier than 4
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/src/PIL/ImageCms.py b/src/PIL/ImageCms.py
index a90efaeb6..d3555694a 100644
--- a/src/PIL/ImageCms.py
+++ b/src/PIL/ImageCms.py
@@ -23,10 +23,9 @@ import operator
 import sys
 from enum import IntEnum, IntFlag
 from functools import reduce
-from typing import Any, Literal, SupportsFloat, SupportsInt, Union
+from typing import Literal, SupportsFloat, SupportsInt, Union
 
-from . import Image, __version__
-from ._deprecate import deprecate
+from . import Image
 from ._typing import SupportsRead
 
 try:
@@ -287,31 +286,6 @@ class ImageCmsTransform(Image.ImagePointHandler):
         proof_intent: Intent = Intent.ABSOLUTE_COLORIMETRIC,
         flags: Flags = Flags.NONE,
     ):
-        supported_modes = (
-            "RGB",
-            "RGBA",
-            "RGBX",
-            "CMYK",
-            "I;16",
-            "I;16L",
-            "I;16B",
-            "YCbCr",
-            "LAB",
-            "L",
-            "1",
-        )
-        for mode in (input_mode, output_mode):
-            if mode not in supported_modes:
-                deprecate(
-                    mode,
-                    12,
-                    {
-                        "L;16": "I;16 or I;16L",
-                        "L:16B": "I;16B",
-                        "YCCA": "YCbCr",
-                        "YCC": "YCbCr",
-                    }.get(mode),
-                )
         if proof is None:
             self.transform = core.buildTransform(
                 input.profile, output.profile, input_mode, output_mode, intent, flags