diff --git a/js/src/ui/Portal/portal.css b/js/src/ui/Portal/portal.css
index 7d66c0a9a..2e6ff8370 100644
--- a/js/src/ui/Portal/portal.css
+++ b/js/src/ui/Portal/portal.css
@@ -51,7 +51,7 @@ $popoverZ: 3600;
   left: 0;
   right: 0;
   opacity: 0.25;
-  z-index: 0;
+  z-index: -1;
 }
 
 .overlay {