diff --git a/zk b/zk
index 1e2ca76..580ce67 100755
--- a/zk
+++ b/zk
@@ -1,3 +1,10 @@
 #!/bin/sh
 
-echo Hello, world
+main() {
+	echo "Hello, world"
+}
+
+name="$(basename "$0")"
+if test "$name" = "zk"; then
+	main
+fi