diff --git a/home-manager/home-manager b/home-manager/home-manager
index 9d10e61e..7187740b 100644
--- a/home-manager/home-manager
+++ b/home-manager/home-manager
@@ -337,6 +337,11 @@ done
 # Get rid of the options.
 shift "$((OPTIND-1))"
 
+if [ $# -eq 0 ]; then
+    doHelp >&2
+    exit 1
+fi
+
 cmd="$1"
 shift 1