--- a/browser/themes/shared/toolbarbuttons.inc.css
+++ b/browser/themes/shared/toolbarbuttons.inc.css
@@ -308,21 +308,17 @@ toolbarbutton.bookmark-item[open="true"]
   transition: background-color .4s;
 }
 
 %ifndef MOZ_PHOTON_THEME
 /* unified back/forward button */
 
 :-moz-any(#back-button, #forward-button) > .toolbarbutton-icon {
   border-color: var(--backbutton-border-color) !important;
-}
-
-:-moz-any(#back-button, #forward-button):not(:hover):not(:active):not([open=true]) > .toolbarbutton-icon,
-:-moz-any(#back-button, #forward-button)[disabled=true] > .toolbarbutton-icon {
-  background: var(--backbutton-background) !important;
+  background: var(--backbutton-background);
 }
 
 #forward-button {
   -moz-box-align: stretch; /* let the button shape grow vertically with the location bar */
   padding: 0 !important;
 }
 
 #forward-button > menupopup {
@@ -371,29 +367,23 @@ toolbarbutton.bookmark-item[open="true"]
 }
 
 #back-button > menupopup {
   margin-top: -1px !important;
 }
 
 #back-button > .toolbarbutton-icon {
 %ifdef MOZ_PHOTON_THEME
+  background: var(--backbutton-background);
   border-color: var(--backbutton-border-color) !important;
 %endif
   border-radius: 10000px !important;
   padding: 7px !important;
 }
 
-%ifdef MOZ_PHOTON_THEME
-#back-button:not(:hover):not(:active):not([open=true]) > .toolbarbutton-icon,
-#back-button[disabled=true] > .toolbarbutton-icon {
-  background: var(--backbutton-background) !important;
-}
-%endif
-
 /* bookmarks menu-button */
 
 #bookmarks-menu-button[cui-areatype="toolbar"] > .toolbarbutton-menubutton-dropmarker {
   -moz-appearance: none !important;
 }
 
 #nav-bar #bookmarks-menu-button[cui-areatype="toolbar"]:not([overflowedItem=true]) > .toolbarbutton-menubutton-dropmarker > .dropmarker-icon {
   padding-top: var(--toolbarbutton-inner-padding);