diff --git a/src/tests/frontend/runner.css b/src/tests/frontend/runner.css
index 946bbe537..8af5440ff 100644
--- a/src/tests/frontend/runner.css
+++ b/src/tests/frontend/runner.css
@@ -18,6 +18,7 @@ body {
 #iframe-container {
   width: 80%;
   height: 100%;
+  overflow: auto hidden;
 }
 
 #iframe-container iframe {