diff --git a/doc/developers/contributing.rst b/doc/developers/contributing.rst
index 3c784cff..a18eafc7 100644
--- a/doc/developers/contributing.rst
+++ b/doc/developers/contributing.rst
@@ -11,7 +11,6 @@ You are welcome to reach out to qde@naccy.de if you need help, or have any quest
 To do
 -----
 
-* Enforce ``clang-format`` and ``clang-tidy`` on all source files.
 * Remove the RPM ``x86_64`` macro `workaround <https://pagure.io/epel/issue/325>`_ from the Fedora ``bpfilter.spec``.
 * Gate the documentation generate in Fedora's ``bpfilter.spec`` with a ``bcond``.
 * Add support for CMake 4.0 and ``ninja``.
diff --git a/tests/check/CMakeLists.txt b/tests/check/CMakeLists.txt
index 7a8056f3..8852bd89 100644
--- a/tests/check/CMakeLists.txt
+++ b/tests/check/CMakeLists.txt
@@ -40,6 +40,7 @@ add_test(NAME "check.checkstyle"
         ${CLANG_FORMAT_BIN}
             --style=file:${CMAKE_SOURCE_DIR}/.clang-format
             --dry-run
+            --Werror
             ${bf_srcs}
 )