diff --git a/Makefile b/Makefile
index 5e1eb2c..3d9264c 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,7 @@ booklet: build/main.pdf
 build/%.pdf: %.tex $(RASTF) Makefile
 	@mkdir -p build
 	@git rev-parse HEAD | dd bs=1 count=10 > build/commit.tex
-	@if [ -n $(git diff head) ]; then echo " dirty" >> build/commit.tex; fi
+	@status=$$(git status --porcelain); if test "x$${status}" != x; then echo " dirty" >> build/commit.tex; fi
 	@if [ -t 1 ]; then echo -e "\033[1;33m[Mashup      ]\033[0m main.tex"; else echo "Mashup"; fi
 	@pdflatex -output-directory build -synctex=1 -interaction=nonstopmode $<
 	@pdflatex -output-directory build -synctex=1 -interaction=nonstopmode $< > /dev/null