diff --git a/src/wp-admin/css/colors/_mixins.scss b/src/wp-admin/css/colors/_mixins.scss
index cfed94c191..9c196e0f3b 100644
--- a/src/wp-admin/css/colors/_mixins.scss
+++ b/src/wp-admin/css/colors/_mixins.scss
@@ -13,7 +13,7 @@
 		background: darken( $button-color, 5% );
 		border-color: darken( $button-color, 15% );
 		color: $text-color;
-		box-shadow: inset 0 1px 0 lighten( $button-color, 10% ),
+		box-shadow: inset 0 1px 0 lighten( $button-color, 10% );
 	}
 
 	&:focus {