diff --git a/src/sbbs3/js_bbs.cpp b/src/sbbs3/js_bbs.cpp
index f9faa22d572979ce304bf06c0ea99f3b84970147..394a06579e285e7fa6fd564bf08c075d93f95811 100644
--- a/src/sbbs3/js_bbs.cpp
+++ b/src/sbbs3/js_bbs.cpp
@@ -1849,6 +1849,8 @@ js_spy(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval)
 	if((sbbs=(sbbs_t*)JS_GetContextPrivate(cx))==NULL)
 		return(JS_FALSE);
 
+	if(!JSVAL_IS_NUMBER(argv[0]))
+		return(JS_FALSE);
 	JS_ValueToInt32(cx,argv[0],&node_num);
 	sbbs->spy(node_num);