diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..74b3d06
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,11 @@
+pdfs := $(wildcard tmp/*.pdf)
+
+all: $(pdfs)
+
+%.pdf: %.out
+	@gropdf -d < $^ > $@
+
+watch:;   @watchman -- trigger . _ 'tmp/*.out' -- make all
+unwatch:; @watchman -- watch-del .
+
+.PHONY: watch unwatch