diff --git a/Makefile b/Makefile
index 0f687a6..1d12793 100644
--- a/Makefile
+++ b/Makefile
@@ -82,7 +82,7 @@ clean:
 	find . -type f -name '*.[od(elf)]' -exec rm -f {} +
 
 format:
-	find . -type f -name '*.[ch]' -exec clang-format -i {} +
+	find kern -type f -name '*.[ch]' -exec clang-format -i {} \;
 
 TOOLCHAIN_DIR := toolchain