--- a/widget/gtk/WidgetStyleCache.cpp
+++ b/widget/gtk/WidgetStyleCache.cpp
@@ -992,16 +992,23 @@ GetWidgetStyleInternal(WidgetNodeType aN
       return GetWidgetStyleWithClass(MOZ_GTK_RADIOMENUITEM,
                                      GTK_STYLE_CLASS_RADIO);
     case MOZ_GTK_CHECKMENUITEM_INDICATOR:
       return GetWidgetStyleWithClass(MOZ_GTK_CHECKMENUITEM,
                                      GTK_STYLE_CLASS_CHECK);
     case MOZ_GTK_PROGRESS_TROUGH:
       return GetWidgetStyleWithClass(MOZ_GTK_PROGRESSBAR,
                                      GTK_STYLE_CLASS_TROUGH);
+    case MOZ_GTK_PROGRESS_CHUNK: {
+      GtkStyleContext* style =
+        GetWidgetStyleWithClass(MOZ_GTK_PROGRESSBAR,
+                                GTK_STYLE_CLASS_PROGRESSBAR);
+      gtk_style_context_remove_class(style, GTK_STYLE_CLASS_TROUGH);
+      return style;
+    }
     case MOZ_GTK_GRIPPER:
       return GetWidgetStyleWithClass(MOZ_GTK_GRIPPER,
                                      GTK_STYLE_CLASS_GRIP);
     case MOZ_GTK_INFO_BAR:
       return GetWidgetStyleWithClass(MOZ_GTK_INFO_BAR,
                                      GTK_STYLE_CLASS_INFO);
     case MOZ_GTK_SPINBUTTON_ENTRY:
       return GetWidgetStyleWithClass(MOZ_GTK_SPINBUTTON,

--- a/widget/gtk/gtk3drawing.cpp
+++ b/widget/gtk/gtk3drawing.cpp
@@ -1371,27 +1371,18 @@ moz_gtk_progressbar_paint(cairo_t *cr, G
     return MOZ_GTK_SUCCESS;
 }
 
 static gint
 moz_gtk_progress_chunk_paint(cairo_t *cr, GdkRectangle* rect,
                              GtkTextDirection direction,
                              WidgetNodeType widget)
 {
-    GtkStyleContext* style;
-
-    if (gtk_check_version(3, 20, 0) != nullptr) {
-      /* Ask for MOZ_GTK_PROGRESS_TROUGH instead of MOZ_GTK_PROGRESSBAR
-       * because ClaimStyleContext() saves/restores that style */
-      style = ClaimStyleContext(MOZ_GTK_PROGRESS_TROUGH, direction);
-      gtk_style_context_remove_class(style, GTK_STYLE_CLASS_TROUGH);
-      gtk_style_context_add_class(style, GTK_STYLE_CLASS_PROGRESSBAR);
-    } else {
-      style = ClaimStyleContext(MOZ_GTK_PROGRESS_CHUNK, direction);
-    }
+    GtkStyleContext* style =
+        ClaimStyleContext(MOZ_GTK_PROGRESS_CHUNK, direction);
 
     if (widget == MOZ_GTK_PROGRESS_CHUNK_INDETERMINATE ||
         widget == MOZ_GTK_PROGRESS_CHUNK_VERTICAL_INDETERMINATE) {
       /**
        * The bar's size and the bar speed are set depending of the progress'
        * size. These could also be constant for all progress bars easily.
        */
       gboolean vertical = (widget == MOZ_GTK_PROGRESS_CHUNK_VERTICAL_INDETERMINATE);