diff --git a/Tools/lint.sh b/Tools/lint.sh
index 841c7d0d92..4dfa619ee8 100755
--- a/Tools/lint.sh
+++ b/Tools/lint.sh
@@ -5,7 +5,7 @@
 fail=0
 
 # Check for clang-format issues.
-for f in $(git diff --name-only --diff-filter=ACMRTUXB); do
+for f in $(git diff --name-only --diff-filter=ACMRTUXB --cached); do
   if ! echo "${f}" | egrep -q "[.](cpp|h|mm)$"; then
     continue
   fi