diff --git a/shell/README.md b/shell/README.md
index 0d083773..7a6600c2 100644
--- a/shell/README.md
+++ b/shell/README.md
@@ -3,7 +3,7 @@
 Currently runs a tiny subset of Lisp. To build and run it from the top-level:
 
 ```sh
-$ ./translate shell/*.mu
+$ ./translate shell/*.mu      # generates disk.img
 $ qemu-system-i386 disk.img
 ```