--- a/browser/themes/osx/browser.css
+++ b/browser/themes/osx/browser.css
@@ -295,25 +295,29 @@ toolbarbutton.bookmark-item:not(.subview
   padding: 1px 8px;
   margin: 0 0 1px;
 }
 
 #personal-bookmarks[cui-areatype="toolbar"]:not([overflowedItem=true]) > #bookmarks-toolbar-placeholder {
   -moz-box-orient: horizontal;
 }
 
+.toolbarbutton-1 > .toolbarbutton-menu-dropmarker,
+.toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker,
 .bookmark-item > .toolbarbutton-menu-dropmarker {
   list-style-image: url("chrome://browser/skin/places/folderDropArrow.png");
   -moz-image-region: rect(0, 7px, 5px, 0);
   margin-top: 1px;
   -moz-margin-start: 3px;
   -moz-margin-end: -2px;
 }
 
 @media (min-resolution: 2dppx) {
+  .toolbarbutton-1 > .toolbarbutton-menu-dropmarker,
+  .toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker,
   .bookmark-item > .toolbarbutton-menu-dropmarker {
     list-style-image: url("chrome://browser/skin/places/folderDropArrow@2x.png");
     -moz-image-region: rect(0, 14px, 10px, 0);
   }
 
   .bookmark-item > .toolbarbutton-menu-dropmarker > .dropmarker-icon {
     width: 7px;
   }
@@ -1075,27 +1079,17 @@ toolbar .toolbarbutton-1 > .toolbarbutto
 
   #main-window:not([customizing]) .toolbarbutton-1:-moz-window-inactive[disabled="true"] > .toolbarbutton-icon,
   #main-window:not([customizing]) .toolbarbutton-1:-moz-window-inactive[disabled="true"] > .toolbarbutton-badge-stack > .toolbarbutton-icon,
   #main-window:not([customizing]) .toolbarbutton-1:-moz-window-inactive > .toolbarbutton-menubutton-button[disabled="true"] > .toolbarbutton-icon {
     opacity: .25;
   }
 }
 
-.toolbarbutton-1 > .toolbarbutton-menu-dropmarker,
-.toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker {
-  list-style-image: url(chrome://browser/skin/toolbarbutton-dropmarker.png);
-}
-
 @media (min-resolution: 2dppx) {
-  .toolbarbutton-1 > .toolbarbutton-menu-dropmarker,
-  .toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker {
-    list-style-image: url(chrome://browser/skin/toolbarbutton-dropmarker@2x.png);
-  }
-
   .toolbarbutton-1 > .toolbarbutton-menu-dropmarker > .dropmarker-icon,
   .toolbarbutton-1 > .toolbarbutton-menubutton-dropmarker > .dropmarker-icon {
     width: 7px;
   }
 }
 
 .toolbarbutton-1 > .toolbarbutton-menu-dropmarker {
   -moz-margin-end: 1px;

--- a/browser/themes/osx/devedition.css
+++ b/browser/themes/osx/devedition.css
@@ -110,20 +110,26 @@
 }
 
 :root[devtoolstheme="dark"] .findbar-closebutton:not(:hover),
 /* Tab styling - make sure to use an inverted icon for the selected tab
    (brighttext only covers the unselected tabs) */
 .tab-close-button[visuallyselected=true]:not(:hover) {
   -moz-image-region: rect(0, 64px, 16px, 48px);
 }
+:root[devtoolstheme="dark"] .toolbarbutton-menu-dropmarker:not(:hover) {
+  -moz-image-region: rect(5px, 7px, 10px, 0);
+}
 @media (min-resolution: 2dppx) {
   :root[devtoolstheme="dark"] .findbar-closebutton:not(:hover),
   .tab-close-button[visuallyselected=true]:not(:hover) {
     -moz-image-region: rect(0, 128px, 32px, 96px);
   }
+  :root[devtoolstheme="dark"] .toolbarbutton-menu-dropmarker:not(:hover) {
+    -moz-image-region: rect(10px, 14px, 20px, 0);
+  }
 }
 
 .ac-type-icon {
   /* Left-align the type icon in awesomebar popup results with the icon in the
      urlbar. */
   -moz-margin-start: 14px;
 }