diff --git a/lisp/startup.el b/lisp/startup.el
index 251f395abd7..a31aa73f7d4 100644
--- a/lisp/startup.el
+++ b/lisp/startup.el
@@ -81,6 +81,9 @@ Elements look like (SWITCH-STRING . HANDLER-FUNCTION).
 HANDLER-FUNCTION receives switch name as sole arg;
 remaining command-line args are in the variable `command-line-args-left'.")
 
+(defvar command-line-args-left nil
+  "List of command-line args not yet processed.")
+
 (defvar command-line-functions nil    ;; lrs 7/31/89
   "List of functions to process unrecognized command-line arguments.
 Each function should access the dynamically bound variables