diff --git a/Makefile b/Makefile
index 4e2b970..f0731a8 100644
--- a/Makefile
+++ b/Makefile
@@ -16,9 +16,10 @@ require_clean_git:
 	git diff-index --cached --quiet --ignore-submodules HEAD --
 	@status=$$(git status --porcelain); \
 	if test "x$${status}" = x; then \
-		echo "No files"; \
+		echo "No untracked files detected"; \
 	else \
-		echo "Untracked files" >&2; \
+		echo "Untracked files detected" >&2; \
+		exit 1
 	fi