diff --git a/Tests/test_file_bufrstub.py b/Tests/test_file_bufrstub.py
index 939e82e77..77ee5b0ea 100644
--- a/Tests/test_file_bufrstub.py
+++ b/Tests/test_file_bufrstub.py
@@ -64,6 +64,9 @@ def test_handler(tmp_path: Path) -> None:
             im.fp.close()
             return Image.new("RGB", (1, 1))
 
+        def is_loaded(self) -> bool:
+            return self.loaded
+
         def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
             self.saved = True
 
@@ -71,10 +74,10 @@ def test_handler(tmp_path: Path) -> None:
     BufrStubImagePlugin.register_handler(handler)
     with Image.open(TEST_FILE) as im:
         assert handler.opened
-        assert not handler.loaded
+        assert not handler.is_loaded()
 
         im.load()
-        assert handler.loaded
+        assert handler.is_loaded()
 
         temp_file = str(tmp_path / "temp.bufr")
         im.save(temp_file)
diff --git a/Tests/test_file_gribstub.py b/Tests/test_file_gribstub.py
index 86a9064fc..aba473d24 100644
--- a/Tests/test_file_gribstub.py
+++ b/Tests/test_file_gribstub.py
@@ -64,6 +64,9 @@ def test_handler(tmp_path: Path) -> None:
             im.fp.close()
             return Image.new("RGB", (1, 1))
 
+        def is_loaded(self) -> bool:
+            return self.loaded
+
         def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
             self.saved = True
 
@@ -71,10 +74,10 @@ def test_handler(tmp_path: Path) -> None:
     GribStubImagePlugin.register_handler(handler)
     with Image.open(TEST_FILE) as im:
         assert handler.opened
-        assert not handler.loaded
+        assert not handler.is_loaded()
 
         im.load()
-        assert handler.loaded
+        assert handler.is_loaded()
 
         temp_file = str(tmp_path / "temp.grib")
         im.save(temp_file)
diff --git a/Tests/test_file_hdf5stub.py b/Tests/test_file_hdf5stub.py
index ee1544c51..8275bd0d8 100644
--- a/Tests/test_file_hdf5stub.py
+++ b/Tests/test_file_hdf5stub.py
@@ -66,6 +66,9 @@ def test_handler(tmp_path: Path) -> None:
             im.fp.close()
             return Image.new("RGB", (1, 1))
 
+        def is_loaded(self) -> bool:
+            return self.loaded
+
         def save(self, im: Image.Image, fp: IO[bytes], filename: str) -> None:
             self.saved = True
 
@@ -73,10 +76,10 @@ def test_handler(tmp_path: Path) -> None:
     Hdf5StubImagePlugin.register_handler(handler)
     with Image.open(TEST_FILE) as im:
         assert handler.opened
-        assert not handler.loaded
+        assert not handler.is_loaded()
 
         im.load()
-        assert handler.loaded
+        assert handler.is_loaded()
 
         temp_file = str(tmp_path / "temp.h5")
         im.save(temp_file)
diff --git a/Tests/test_file_png.py b/Tests/test_file_png.py
index 0f0976802..a8b50a6d4 100644
--- a/Tests/test_file_png.py
+++ b/Tests/test_file_png.py
@@ -775,7 +775,7 @@ class TestFilePng:
 
         mystdout: MyStdOut | BytesIO = MyStdOut() if buffer else BytesIO()
 
-        sys.stdout = mystdout
+        sys.stdout = mystdout  # type: ignore[assignment]
 
         with Image.open(TEST_PNG_FILE) as im:
             im.save(sys.stdout, "PNG")
diff --git a/Tests/test_file_ppm.py b/Tests/test_file_ppm.py
index 0a61830a4..d6451ec18 100644
--- a/Tests/test_file_ppm.py
+++ b/Tests/test_file_ppm.py
@@ -373,7 +373,7 @@ def test_save_stdout(buffer: bool) -> None:
 
     mystdout: MyStdOut | BytesIO = MyStdOut() if buffer else BytesIO()
 
-    sys.stdout = mystdout
+    sys.stdout = mystdout  # type: ignore[assignment]
 
     with Image.open(TEST_FILE) as im:
         im.save(sys.stdout, "PPM")
diff --git a/Tests/test_file_psd.py b/Tests/test_file_psd.py
index 484a1be8f..ddae8f235 100644
--- a/Tests/test_file_psd.py
+++ b/Tests/test_file_psd.py
@@ -162,7 +162,7 @@ def test_combined_larger_than_size() -> None:
         ("Tests/images/timeout-dedc7a4ebd856d79b4359bbcc79e8ef231ce38f6.psd", OSError),
     ],
 )
-def test_crashes(test_file: str, raises) -> None:
+def test_crashes(test_file: str, raises: type[Exception]) -> None:
     with open(test_file, "rb") as f:
         with pytest.raises(raises):
             with Image.open(f):
diff --git a/Tests/test_file_tiff_metadata.py b/Tests/test_file_tiff_metadata.py
index 8b816aa4f..1e0310001 100644
--- a/Tests/test_file_tiff_metadata.py
+++ b/Tests/test_file_tiff_metadata.py
@@ -11,7 +11,11 @@ from PIL.TiffImagePlugin import IFDRational
 
 from .helper import assert_deep_equal, hopper
 
-TAG_IDS = {info.name: info.value for info in TiffTags.TAGS_V2.values()}
+TAG_IDS: dict[str, int] = {
+    info.name: info.value
+    for info in TiffTags.TAGS_V2.values()
+    if info.value is not None
+}
 
 
 def test_rt_metadata(tmp_path: Path) -> None:
@@ -411,8 +415,8 @@ def test_empty_values() -> None:
     info = TiffImagePlugin.ImageFileDirectory_v2(head)
     info.load(data)
     # Should not raise ValueError.
-    info = dict(info)
-    assert 33432 in info
+    info_dict = dict(info)
+    assert 33432 in info_dict
 
 
 def test_photoshop_info(tmp_path: Path) -> None:
diff --git a/Tests/test_file_webp.py b/Tests/test_file_webp.py
index 1caf032f6..cbc905de4 100644
--- a/Tests/test_file_webp.py
+++ b/Tests/test_file_webp.py
@@ -5,6 +5,7 @@ import re
 import sys
 import warnings
 from pathlib import Path
+from typing import Any
 
 import pytest
 
@@ -70,7 +71,9 @@ class TestFileWebp:
             # dwebp -ppm ../../Tests/images/hopper.webp -o hopper_webp_bits.ppm
             assert_image_similar_tofile(image, "Tests/images/hopper_webp_bits.ppm", 1.0)
 
-    def _roundtrip(self, tmp_path: Path, mode, epsilon, args={}) -> None:
+    def _roundtrip(
+        self, tmp_path: Path, mode: str, epsilon: float, args: dict[str, Any] = {}
+    ) -> None:
         temp_file = str(tmp_path / "temp.webp")
 
         hopper(mode).save(temp_file, **args)
diff --git a/Tests/test_image.py b/Tests/test_image.py
index a8f61d677..5b1ba6289 100644
--- a/Tests/test_image.py
+++ b/Tests/test_image.py
@@ -8,7 +8,7 @@ import sys
 import tempfile
 import warnings
 from pathlib import Path
-from typing import IO
+from typing import IO, Any
 
 import pytest
 
@@ -175,11 +175,19 @@ class TestImage:
     def test_fp_name(self, tmp_path: Path) -> None:
         temp_file = str(tmp_path / "temp.jpg")
 
-        class FP:
+        class FP(io.BytesIO):
             name: str
 
-            def write(self, b: bytes) -> None:
-                pass
+            if sys.version_info >= (3, 12):
+                from collections.abc import Buffer
+
+                def write(self, data: Buffer) -> int:
+                    return len(data)
+
+            else:
+
+                def write(self, data: Any) -> int:
+                    return len(data)
 
         fp = FP()
         fp.name = temp_file
diff --git a/Tests/test_image_array.py b/Tests/test_image_array.py
index d7e6c562c..bb6064882 100644
--- a/Tests/test_image_array.py
+++ b/Tests/test_image_array.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from typing import Any
+from typing import TYPE_CHECKING, Any
 
 import pytest
 from packaging.version import parse as parse_version
@@ -13,13 +13,16 @@ numpy = pytest.importorskip("numpy", reason="NumPy not installed")
 
 im = hopper().resize((128, 100))
 
+if TYPE_CHECKING:
+    import numpy.typing as npt
+
 
 def test_toarray() -> None:
     def test(mode: str) -> tuple[tuple[int, ...], str, int]:
         ai = numpy.array(im.convert(mode))
         return ai.shape, ai.dtype.str, ai.nbytes
 
-    def test_with_dtype(dtype) -> None:
+    def test_with_dtype(dtype: npt.DTypeLike) -> None:
         ai = numpy.array(im, dtype=dtype)
         assert ai.dtype == dtype
 
diff --git a/Tests/test_imagefile.py b/Tests/test_imagefile.py
index 00cdec952..a269b846a 100644
--- a/Tests/test_imagefile.py
+++ b/Tests/test_imagefile.py
@@ -351,7 +351,9 @@ class TestPyEncoder(CodecsTest):
             ImageFile._save(
                 im, fp, [("MOCK", (xoff, yoff, -10, yoff + ysize), 0, "RGB")]
             )
-        assert MockPyEncoder.last.cleanup_called
+        last: MockPyEncoder | None = MockPyEncoder.last
+        assert last
+        assert last.cleanup_called
 
         with pytest.raises(ValueError):
             ImageFile._save(
diff --git a/Tests/test_imagefont.py b/Tests/test_imagefont.py
index c3906de24..e50198087 100644
--- a/Tests/test_imagefont.py
+++ b/Tests/test_imagefont.py
@@ -548,7 +548,7 @@ def test_find_font(
 
             def loadable_font(
                 filepath: str, size: int, index: int, encoding: str, *args: Any
-            ):
+            ) -> ImageFont.FreeTypeFont:
                 _freeTypeFont = getattr(ImageFont, "_FreeTypeFont")
                 if filepath == path_to_fake:
                     return _freeTypeFont(FONT_PATH, size, index, encoding, *args)
diff --git a/Tests/test_imagewin_pointers.py b/Tests/test_imagewin_pointers.py
index e6c312a0c..c23a5c690 100644
--- a/Tests/test_imagewin_pointers.py
+++ b/Tests/test_imagewin_pointers.py
@@ -45,21 +45,22 @@ if is_win32():
     memcpy = ctypes.cdll.msvcrt.memcpy
     memcpy.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_size_t]
 
-    CreateCompatibleDC = ctypes.windll.gdi32.CreateCompatibleDC
+    windll = getattr(ctypes, "windll")
+    CreateCompatibleDC = windll.gdi32.CreateCompatibleDC
     CreateCompatibleDC.argtypes = [ctypes.wintypes.HDC]
     CreateCompatibleDC.restype = ctypes.wintypes.HDC
 
-    DeleteDC = ctypes.windll.gdi32.DeleteDC
+    DeleteDC = windll.gdi32.DeleteDC
     DeleteDC.argtypes = [ctypes.wintypes.HDC]
 
-    SelectObject = ctypes.windll.gdi32.SelectObject
+    SelectObject = windll.gdi32.SelectObject
     SelectObject.argtypes = [ctypes.wintypes.HDC, ctypes.wintypes.HGDIOBJ]
     SelectObject.restype = ctypes.wintypes.HGDIOBJ
 
-    DeleteObject = ctypes.windll.gdi32.DeleteObject
+    DeleteObject = windll.gdi32.DeleteObject
     DeleteObject.argtypes = [ctypes.wintypes.HGDIOBJ]
 
-    CreateDIBSection = ctypes.windll.gdi32.CreateDIBSection
+    CreateDIBSection = windll.gdi32.CreateDIBSection
     CreateDIBSection.argtypes = [
         ctypes.wintypes.HDC,
         ctypes.c_void_p,
diff --git a/Tests/test_psdraw.py b/Tests/test_psdraw.py
index c3afa9089..130ffa863 100644
--- a/Tests/test_psdraw.py
+++ b/Tests/test_psdraw.py
@@ -59,7 +59,7 @@ def test_stdout(buffer: bool) -> None:
 
     mystdout: MyStdOut | BytesIO = MyStdOut() if buffer else BytesIO()
 
-    sys.stdout = mystdout
+    sys.stdout = mystdout  # type: ignore[assignment]
 
     ps = PSDraw.PSDraw()
     _create_document(ps)