diff --git a/gtk/theme/Adwaita/_common.scss b/gtk/theme/Adwaita/_common.scss
index 5fd176598b..b2f7bfe7f3 100644
--- a/gtk/theme/Adwaita/_common.scss
+++ b/gtk/theme/Adwaita/_common.scss
@@ -1723,7 +1723,7 @@ headerbar { // headerbar border rounding
 // Development versions of apps to use a differently styled headerbar
 
 window.devel {    
-  headerbar {
+  headerbar:last-child {
     background: transparent -gtk-icontheme("system-run-symbolic") 90% 0/256px 256px no-repeat,
                 linear-gradient(to left, mix($selected_bg_color, $bg_color, 10%) 8%, $bg_color 25%);
     color: transparentize($fg_color,.9);
@@ -4618,4 +4618,4 @@ popover.emoji-completion contents row box {
 
 popover.emoji-completion .emoji:hover {
   background-color: $popover_hover_color;
-}
+}
\ No newline at end of file