diff --git a/browser/base/content/test/static/browser_parsable_css.js b/browser/base/content/test/static/browser_parsable_css.js
index 70c24dc08b84..ebbceb45ba90 100644
--- a/browser/base/content/test/static/browser_parsable_css.js
+++ b/browser/base/content/test/static/browser_parsable_css.js
@@ -46,6 +46,11 @@ let whitelist = [
   {sourceName: /(?:res|gre-resources)\/forms\.css$/i,
    errorMessage: /Unknown property.*overflow-clip-box/i,
    isFromDevTools: false},
+  // The '-moz-menulist-button' value is only supported in chrome and UA sheets
+  // but forms.css is loaded as a document sheet by this test.
+  {sourceName: /(?:res|gre-resources)\/forms\.css$/i,
+   errorMessage: /Error in parsing value for ‘-moz-appearance’\. Declaration dropped\./i,
+   isFromDevTools: false},
   // These variables are declared somewhere else, and error when we load the
   // files directly. They're all marked intermittent because their appearance
   // in the error console seems to not be consistent.
diff --git a/layout/style/res/forms.css b/layout/style/res/forms.css
index 64b28e7bf384..ef99efa3da71 100644
--- a/layout/style/res/forms.css
+++ b/layout/style/res/forms.css
@@ -284,7 +284,7 @@ select > button {
   background-image: url("arrow.gif") !important;
   background-repeat: no-repeat !important;
   background-position: center !important;
-  -moz-appearance: menulist-button;
+  -moz-appearance: -moz-menulist-button;
 
   /* Make sure to size correctly if the combobox has a non-auto height. */
   block-size: 100% ! important;
diff --git a/toolkit/themes/linux/global/dropmarker.css b/toolkit/themes/linux/global/dropmarker.css
index 5b44ac40ead4..459ccf7e3408 100644
--- a/toolkit/themes/linux/global/dropmarker.css
+++ b/toolkit/themes/linux/global/dropmarker.css
@@ -3,5 +3,5 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 dropmarker {
-  -moz-appearance: menulist-button;
+  -moz-appearance: -moz-menulist-button;
 }
diff --git a/toolkit/themes/linux/global/menulist.css b/toolkit/themes/linux/global/menulist.css
index d10ac8cd7b71..16ea100ec6bc 100644
--- a/toolkit/themes/linux/global/menulist.css
+++ b/toolkit/themes/linux/global/menulist.css
@@ -66,7 +66,7 @@ menulist[editable="true"] {
 
 menulist[editable="true"] > .menulist-dropmarker {
   display: -moz-box;
-  -moz-appearance: menulist-button;
+  -moz-appearance: -moz-menulist-button;
 }
 
 html|*.menulist-editable-input {
diff --git a/toolkit/themes/osx/global/dropmarker.css b/toolkit/themes/osx/global/dropmarker.css
index bdf160523ed9..2a85376eb419 100644
--- a/toolkit/themes/osx/global/dropmarker.css
+++ b/toolkit/themes/osx/global/dropmarker.css
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 dropmarker {
-  -moz-appearance: menulist-button;
+  -moz-appearance: -moz-menulist-button;
   width: 16px;
   -moz-box-align: center;
   -moz-box-pack: center;
diff --git a/toolkit/themes/windows/global/dropmarker.css b/toolkit/themes/windows/global/dropmarker.css
index 20717f2f212d..5b98324dec86 100644
--- a/toolkit/themes/windows/global/dropmarker.css
+++ b/toolkit/themes/windows/global/dropmarker.css
@@ -3,7 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 dropmarker {
-  -moz-appearance: menulist-button;
+  -moz-appearance: -moz-menulist-button;
   width: 16px;
   height: 16px;
   -moz-box-align: center;