diff --git a/src/main/frontend/background_tasks.cljs b/src/main/frontend/background_tasks.cljs
index 2e61df01fd..cf7c994bbc 100644
--- a/src/main/frontend/background_tasks.cljs
+++ b/src/main/frontend/background_tasks.cljs
@@ -18,5 +18,7 @@
 (c.m/run-background-task
  ::sync-to-worker-network-online-status
  (m/reduce
-  (fn [_ online?] (state/<invoke-db-worker :thread-api/update-thread-atom :thread-atom/online-event online?))
-  flows/network-online-event-flow))
+  (fn [_ [online? db-worker-ready?]]
+    (when db-worker-ready?
+      (state/<invoke-db-worker :thread-api/update-thread-atom :thread-atom/online-event online?)))
+  (m/latest vector flows/network-online-event-flow state/db-worker-ready-flow)))
diff --git a/src/main/frontend/state.cljs b/src/main/frontend/state.cljs
index 698653b889..c443e6a2b8 100644
--- a/src/main/frontend/state.cljs
+++ b/src/main/frontend/state.cljs
@@ -35,6 +35,12 @@
 (defonce *db-worker (atom nil))
 (defonce *editor-info (atom nil))
 
+(def db-worker-ready-flow
+  "`<invoke-db-worker` throws err if `*db-worker` not ready yet.
+  Use this flow to wait till db-worker ready."
+  (->> (m/watch *db-worker)
+       (m/eduction (map some?))))
+
 (defn- <invoke-db-worker*
   [qkw direct-pass-args? args-list]
   (let [worker @*db-worker]