diff --git a/tools/check_format_test_helper.py b/tools/check_format_test_helper.py
index 7ac9f5af94ea3..17ad7edf9f583 100755
--- a/tools/check_format_test_helper.py
+++ b/tools/check_format_test_helper.py
@@ -134,6 +134,7 @@ def checkFileExpectingOK(filename):
   errors += fixFileExpectingSuccess("header_order.cc")
   errors += fixFileExpectingSuccess("license.BUILD")
   errors += fixFileExpectingSuccess("bad_envoy_build_sys_ref.BUILD")
+  errors += fixFileExpectingSuccess("proto_format.proto")
   errors += fixFileExpectingFailure("no_namespace_envoy.cc",
                                     "Unable to find Envoy namespace or NOLINT(namespace-envoy)")
   errors += fixFileExpectingFailure("mutex.cc",
@@ -161,6 +162,8 @@ def checkFileExpectingOK(filename):
   errors += checkFileExpectingError("license.BUILD", "envoy_build_fixer check failed")
   errors += checkFileExpectingError("bad_envoy_build_sys_ref.BUILD",
                                     "Superfluous '@envoy//' prefix")
+  errors += checkFileExpectingError("proto_format.proto", "clang-format check failed")
+
   errors += checkFileExpectingOK("ok_file.cc")
 
   errors += fixFileExpectingFailure("proto.BUILD",
diff --git a/tools/testdata/check_format/proto_format.proto b/tools/testdata/check_format/proto_format.proto
new file mode 100644
index 0000000000000..b31d9dfa47db3
--- /dev/null
+++ b/tools/testdata/check_format/proto_format.proto
@@ -0,0 +1 @@
+// This commment is too long for the line-limit built into our clang configuration, so it will need to be wrapped.
diff --git a/tools/testdata/check_format/proto_format.proto.gold b/tools/testdata/check_format/proto_format.proto.gold
new file mode 100644
index 0000000000000..db5b8dea9cc7b
--- /dev/null
+++ b/tools/testdata/check_format/proto_format.proto.gold
@@ -0,0 +1,2 @@
+// This commment is too long for the line-limit built into our clang
+// configuration, so it will need to be wrapped.