diff --git a/gtk/theme/Default/_common.scss b/gtk/theme/Default/_common.scss
index 4c233f80a7..9b44517af5 100644
--- a/gtk/theme/Default/_common.scss
+++ b/gtk/theme/Default/_common.scss
@@ -544,6 +544,7 @@ button {
         transition: $button_transition;
         transition-duration: 500ms;
       }
+      &.keyboard-activating,
       &:active,
       &:checked {
         @include button(undecorated-active);