diff --git a/src/plugins/css/preflight.css b/src/plugins/css/preflight.css
index ec14c3762..e26039599 100644
--- a/src/plugins/css/preflight.css
+++ b/src/plugins/css/preflight.css
@@ -25,7 +25,8 @@ pre {
 }
 
 button {
-  background: transparent;
+  background-color: transparent;
+  background-image: none;
   padding: 0;
 }