diff --git a/www/slide/app-slide.less b/www/slide/app-slide.less
index 6ea85e458..f9bb7b09c 100644
--- a/www/slide/app-slide.less
+++ b/www/slide/app-slide.less
@@ -176,7 +176,7 @@ div#cp-app-slide-modal {
         position: fixed;
         top: 0px;
         left: 0px;
-        z-index: 100000;
+        z-index: 1000000; // one order of magnitude higher than alertify
         height: 100vh;
         width: 100%;
     }
@@ -329,4 +329,4 @@ p {
 
 pre.cp-slide-css-error {
     color: white;
-}
\ No newline at end of file
+}