diff --git a/pyproject.toml b/pyproject.toml
index bfdae9a..2d87d6d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -49,7 +49,7 @@ dev = [
     "pytest ~= 8.3",
     "packaging ~= 25.0",
     "coverage ~= 7.6",
-    "diff_cover == 9.6.0",
+    "diff_cover == 9.7.2",
     "codecov == 2.1.12",
     # Required for showing OpenSSL version in test_ci.
     "pyOpenSSL",