diff --git a/tools/check_format.sh b/tools/check_format.sh
index 019411e..d32014b 100755
--- a/tools/check_format.sh
+++ b/tools/check_format.sh
@@ -76,7 +76,7 @@ done <<< $(git ls-files -s '*.sh')
 
 
 echo "Checking for signoff in commit message..."
-if ! git log -n 1 --format=%B | grep -q "^Signed-off-by:" ; then
+if ! git log -n 1 --format=%B --no-merges | grep -q "^Signed-off-by:" ; then
     echo "  Commit not signed off. Please read src/CONTRIBUTING.md"
     rc=1
 fi