diff --git a/data/theme/gnome-shell-sass/widgets/_screen-shield.scss b/data/theme/gnome-shell-sass/widgets/_screen-shield.scss
index 00c549a53..e289fdbaf 100644
--- a/data/theme/gnome-shell-sass/widgets/_screen-shield.scss
+++ b/data/theme/gnome-shell-sass/widgets/_screen-shield.scss
@@ -66,7 +66,7 @@
 }
 
 #lockDialogGroup {
-  background-color: lighten(#2e3436, 8%);
+  background-color: $system_bg_color;
 }
 
 #unlockDialogNotifications {