diff --git a/src/tests/frontend/runner.css b/src/tests/frontend/runner.css
index 2ae0d58de..72f1e0475 100644
--- a/src/tests/frontend/runner.css
+++ b/src/tests/frontend/runner.css
@@ -22,6 +22,7 @@ body {
 }
 
 #iframe-container iframe {
+  border: 0;
   height: 100%;
   width:100%;
 }