diff --git a/data/theme/gnome-shell-sass/widgets/_window-picker.scss b/data/theme/gnome-shell-sass/widgets/_window-picker.scss
index 1432a3bf8..7592aa4c9 100644
--- a/data/theme/gnome-shell-sass/widgets/_window-picker.scss
+++ b/data/theme/gnome-shell-sass/widgets/_window-picker.scss
@@ -44,3 +44,10 @@ $window_close_button_padding: 3px;
     background-color: darken($osd_bg_color, 5%);
   }
 }
+
+.workspace-background {
+  // keep in sync with BACKGROUND_CORNER_RADIUS_PIXELS in workspace.js
+  border-radius: 30px;
+  background-color: $osd_bg_color;
+  box-shadow: 0 -4px 16px 4px transparentize(darken($osd_bg_color, 30%), 0.7);
+}