diff --git a/gtk/theme/HighContrast/_common.scss b/gtk/theme/HighContrast/_common.scss
index 19e4e3f7ff..44a9e2e1d6 100644
--- a/gtk/theme/HighContrast/_common.scss
+++ b/gtk/theme/HighContrast/_common.scss
@@ -461,7 +461,7 @@ button {
 
 // all the following is for the +|- buttons on inline toolbars, that way
 // should really be reprecated...
-.inline-toolbar GtkToolButton > button { // redefining the button look is
+.inline-toolbar toolbutton > button { // redefining the button look is
                                                // needed since those are flat...
   @include button(normal, $edge: none); // the box-shadow outset doesn't work
                                           // in this case, hence $edge: none
@@ -474,7 +474,7 @@ button {
   &:backdrop:insensitive { @include button(backdrop-insensitive); }
   &:backdrop:insensitive:active { @include button(backdrop-insensitive-active);}
 }
-toolbar.inline-toolbar GtkToolButton { // .inline-toolbar.toolbar here for
+toolbar.inline-toolbar toolbutton { // .inline-toolbar.toolbar here for
                                         // higher specificity than the previous
                                         // "button look" selector
   & > button.flat {
diff --git a/gtk/theme/HighContrast/gtk.css b/gtk/theme/HighContrast/gtk.css
index 0c58baa919..cb7f7161e0 100644
--- a/gtk/theme/HighContrast/gtk.css
+++ b/gtk/theme/HighContrast/gtk.css
@@ -617,28 +617,28 @@ button {
   .primary-toolbar button {
     icon-shadow: none; }
 
-.inline-toolbar GtkToolButton > button {
+.inline-toolbar toolbutton > button {
   border-width: 2px;
   border-style: solid;
   color: #000;
   background-image: none;
   background-color: #fff;
   border-color: gray; }
-  .inline-toolbar GtkToolButton > button:hover {
+  .inline-toolbar toolbutton > button:hover {
     border-width: 2px;
     border-style: solid;
     color: #000;
     background-color: #fff;
     border-color: gray;
     background-image: none; }
-  .inline-toolbar GtkToolButton > button:active {
+  .inline-toolbar toolbutton > button:active {
     border-width: 2px;
     border-style: solid;
     background-image: none;
     color: white;
     background-color: black;
     border-color: gray; }
-  .inline-toolbar GtkToolButton > button:insensitive {
+  .inline-toolbar toolbutton > button:insensitive {
     border-width: 2px;
     border-style: solid;
     color: gray;
@@ -647,14 +647,14 @@ button {
     background-image: none;
     text-shadow: none;
     icon-shadow: none; }
-  .inline-toolbar GtkToolButton > button:insensitive:active {
+  .inline-toolbar toolbutton > button:insensitive:active {
     border-width: 2px;
     border-style: solid;
     color: gray;
     border-color: gray;
     background-image: none;
     background-color: white; }
-  .inline-toolbar GtkToolButton > button:backdrop {
+  .inline-toolbar toolbutton > button:backdrop {
     border-width: 2px;
     border-style: solid;
     color: #000;
@@ -663,21 +663,21 @@ button {
     background-image: none;
     text-shadow: none;
     icon-shadow: none; }
-  .inline-toolbar GtkToolButton > button:backdrop:active {
+  .inline-toolbar toolbutton > button:backdrop:active {
     border-width: 2px;
     border-style: solid;
     color: white;
     background-color: #8d8d8d;
     border-color: #8d8d8d;
     background-image: none; }
-  .inline-toolbar GtkToolButton > button:backdrop:insensitive {
+  .inline-toolbar toolbutton > button:backdrop:insensitive {
     border-width: 2px;
     border-style: solid;
     color: gray;
     background-color: white;
     border-color: #8d8d8d;
     background-image: none; }
-  .inline-toolbar GtkToolButton > button:backdrop:insensitive:active {
+  .inline-toolbar toolbutton > button:backdrop:insensitive:active {
     border-width: 2px;
     border-style: solid;
     color: gray;
@@ -685,17 +685,17 @@ button {
     background-image: none;
     background-color: #f6f6f6; }
 
-toolbar.inline-toolbar GtkToolButton > button.flat, toolbar.inline-toolbar GtkToolButton > .sidebar-button.button {
+toolbar.inline-toolbar toolbutton > button.flat, toolbar.inline-toolbar toolbutton > .sidebar-button.button {
   border-radius: 0;
   border-left-style: none; }
-toolbar.inline-toolbar GtkToolButton:first-child > button.flat, toolbar.inline-toolbar GtkToolButton:first-child > .sidebar-button.button {
+toolbar.inline-toolbar toolbutton:first-child > button.flat, toolbar.inline-toolbar toolbutton:first-child > .sidebar-button.button {
   border-radius: 3px 0 0 3px;
   border-left-style: solid; }
-toolbar.inline-toolbar GtkToolButton:last-child > button.flat, toolbar.inline-toolbar GtkToolButton:last-child > .sidebar-button.button {
+toolbar.inline-toolbar toolbutton:last-child > button.flat, toolbar.inline-toolbar toolbutton:last-child > .sidebar-button.button {
   border-radius: 0 3px 3px 0; }
-toolbar.inline-toolbar GtkToolButton:last-child:dir(rtl) > button.flat, toolbar.inline-toolbar GtkToolButton:last-child:dir(rtl) > .sidebar-button.button {
+toolbar.inline-toolbar toolbutton:last-child:dir(rtl) > button.flat, toolbar.inline-toolbar toolbutton:last-child:dir(rtl) > .sidebar-button.button {
   border-right-style: solid; }
-toolbar.inline-toolbar GtkToolButton:only-child > button.flat, toolbar.inline-toolbar GtkToolButton:only-child > .sidebar-button.button {
+toolbar.inline-toolbar toolbutton:only-child > button.flat, toolbar.inline-toolbar toolbutton:only-child > .sidebar-button.button {
   border-radius: 3px;
   border-style: solid; }