--- a/browser/themes/shared/incontentprefs/search.css
+++ b/browser/themes/shared/incontentprefs/search.css
@@ -16,16 +16,20 @@
   /* Allow a little visual space to separate the radio from the image above it. */
   margin-top: 10px;
 }
 
 .searchBarShownImage  {
   list-style-image: url("chrome://browser/skin/preferences/in-content/search-bar.svg");
 }
 
+.searchBarImage:-moz-locale-dir(rtl) {
+  transform: scaleX(-1);
+}
+
 #defaultEngine {
  margin-inline-start: 0;
 }
 
 #defaultEngine > .menulist-label-box > .menulist-icon {
   height: 16px;
 }