diff --git a/awesome.c b/awesome.c
index ef5d18f6..8e8d5dde 100644
--- a/awesome.c
+++ b/awesome.c
@@ -524,6 +524,9 @@ main(int argc, char **argv)
           case 'r':
             replace_wm = true;
             break;
+          default:
+            exit_help(EXIT_FAILURE);
+            break;
         }
 
     /* Get XDG basedir data */