diff --git a/GNUmakefile b/GNUmakefile
new file mode 100644
index 0000000..50f836d
--- /dev/null
+++ b/GNUmakefile
@@ -0,0 +1,6 @@
+.PHONY: all zsh
+
+all: zsh
+
+zsh:
+	$(MAKE) -C $@