diff --git a/customize.dist/src/less/toolbar.less b/customize.dist/src/less/toolbar.less
index 91afca6ae..cbbbd9dd2 100644
--- a/customize.dist/src/less/toolbar.less
+++ b/customize.dist/src/less/toolbar.less
@@ -56,7 +56,7 @@
     display: flex;
     overflow: visible;
     iframe {
-        height: auto;
+        height: 100%;
         width: 100%;
     }
 }