diff --git a/scripts/format-check.sh b/scripts/format-check.sh
index aec4514..cdc3418 100755
--- a/scripts/format-check.sh
+++ b/scripts/format-check.sh
@@ -3,7 +3,7 @@
 wget https://llvm.org/svn/llvm-project/cfe/trunk/tools/clang-format/git-clang-format
 chmod +x git-clang-format
 
-CLANG_FORMAT_OUTPUT=$(./git-clang-format --diff)
+CLANG_FORMAT_OUTPUT=$(./git-clang-format HEAD^ HEAD --diff)
 if [[ ! $CLANG_FORMAT_OUTPUT == "no modified files to format" ]]; then
   echo "Failed clang format check:"
   echo "${CLANG_FORMAT_OUTPUT}"