diff --git a/tl/src/tl/events.cljs b/tl/src/tl/events.cljs
index 1390cea..9a63411 100644
--- a/tl/src/tl/events.cljs
+++ b/tl/src/tl/events.cljs
@@ -90,7 +90,9 @@
 (rf/reg-event-db ::open-draft
                  (fn [db _]
                    (-> db
-                       (assoc-in [:scene :groups (keyword (gensym "ann-"))]
+                       ;; uuid, not gensym: gensym's counter resets each page load, so a
+                       ;; fresh annotation would reuse a prior gid and clobber it on merge.
+                       (assoc-in [:scene :groups (keyword (str "ann-" (random-uuid)))]
                                  {:type :annotation :parent (peek (get-in db [:view :stack]))
                                   :draft :new :name "" :color "#4e8fc2" :marks []})
                        (assoc-in [:view :pt] :new))))