diff --git a/js/modal.js b/js/modal.js
index 831649f..d0358bc 100644
--- a/js/modal.js
+++ b/js/modal.js
@@ -346,7 +346,7 @@
       }
     }
 
-    if (!speed) {
+    if (!speed && 0 !== speed) {
       speed = 'fast';
     }