diff --git a/Tests/test_file_tiff.py b/Tests/test_file_tiff.py
index 502d9df9a..050bfe578 100644
--- a/Tests/test_file_tiff.py
+++ b/Tests/test_file_tiff.py
@@ -990,6 +990,10 @@ class TestFileTiff:
 
     @pytest.mark.timeout(6)
     @pytest.mark.filterwarnings("ignore:Truncated File Read")
+    @pytest.mark.xfail(
+        "PILLOW_VALGRIND_TEST" in os.environ,
+        reason="Valgrind is slower"
+    )
     def test_timeout(self, monkeypatch: pytest.MonkeyPatch) -> None:
         with Image.open("Tests/images/timeout-6646305047838720") as im:
             monkeypatch.setattr(ImageFile, "LOAD_TRUNCATED_IMAGES", True)
@@ -1002,6 +1006,10 @@ class TestFileTiff:
         ],
     )
     @pytest.mark.timeout(2)
+    @pytest.mark.xfail(
+        "PILLOW_VALGRIND_TEST" in os.environ,
+        reason="Valgrind is slower"
+    )
     def test_oom(self, test_file: str) -> None:
         with pytest.raises(UnidentifiedImageError):
             with pytest.warns(UserWarning):