diff --git a/src/static/css/iframe_editor.css b/src/static/css/iframe_editor.css
index 9aa003aaf..033eeb66a 100644
--- a/src/static/css/iframe_editor.css
+++ b/src/static/css/iframe_editor.css
@@ -58,9 +58,11 @@ body.doesWrap {
   white-space: normal;
 }
 
-body.doesWrap:not(.noprewrap) > div{
-  /* Related to #1766 */
-  white-space: pre-wrap;
+@-moz-document url-prefix() {
+  body.doesWrap:not(.noprewrap) > div{
+    /* Related to #1766 */
+    white-space: pre-wrap;
+  }
 }
 
 #innerdocbody {