diff --git a/theme/standard/styles_moz.css b/theme/standard/styles_moz.css
index 7e9e594b040..66d076403be 100644
--- a/theme/standard/styles_moz.css
+++ b/theme/standard/styles_moz.css
@@ -130,6 +130,10 @@
   -moz-border-radius:20px;
 }
 
+.editing .block_course_summary .content {
+  -moz-border-radius-topleft:0;
+  -moz-border-radius-topright:0;
+}
 
 
 /***