diff --git a/tools/check-formatting.sh b/tools/check-formatting.sh
index 029a3a05..5e5699d5 100755
--- a/tools/check-formatting.sh
+++ b/tools/check-formatting.sh
@@ -12,8 +12,9 @@ ALL_OK=1
 
 for f in ${SOURCES[@]}
 do
-    clang-format -n $f 2>&1 | grep ".*" >/dev/null
-    if [ "$?" = "0" ]
+    clang-format -n $f 2>&1 | grep -q ^
+    RESULT=$?
+    if [ "$RESULT" = "0" ]
     then
         echo "File $f needs formatting"
         ALL_OK=0