diff --git a/tools/pre-commit.hooks/clang-format.hook b/tools/pre-commit.hooks/clang-format.hook
index 878c688ec11b61317e875ac6fe44d6dc84d8a0f2..ece9ebc598e3fa63d1d76409dc0068854aaec851 100644
--- a/tools/pre-commit.hooks/clang-format.hook
+++ b/tools/pre-commit.hooks/clang-format.hook
@@ -15,6 +15,9 @@ fi
 # https://medicineyeh.wordpress.com/2017/07/13/clang-format-with-pragma/
 shift
 perl -i -pe 's|^\s+#pragma\s+omp|// <TRICKY-CLANG-FORMAT-PRAGMA-FIX> #pragma omp|' "$@"
+(
+# remove clang format ios_io folder
 flist=$(echo "$@" | perl -pe 's|src/ios_io/[^ ]*||')
 clang-format -i $flist
+)
 perl -i -pe 's|// <TRICKY-CLANG-FORMAT-PRAGMA-FIX> ||' "$@"