diff --git a/ui/src/components/rects/RectPad.vue b/ui/src/components/rects/RectPad.vue
index 9236f70..666a1fa 100644
--- a/ui/src/components/rects/RectPad.vue
+++ b/ui/src/components/rects/RectPad.vue
@@ -53,6 +53,10 @@ export default class RectPad extends Vue {
   private rectangles: Rectangle[] = [];
 
   private on_pointerdown(event: MouseEvent) {
+    if (this.preview_state.visible) {
+      return;
+    }
+
     this.preview_state.visible = true;
     this.preview_state.corner1 = get_event_thous(event);
     this.preview_state.corner2 = get_event_thous(event);