diff --git a/web/src/lib/pwa.ts b/web/src/lib/pwa.ts
index b59f62f..af1b392 100644
--- a/web/src/lib/pwa.ts
+++ b/web/src/lib/pwa.ts
@@ -47,6 +47,20 @@ export function registerServiceWorker() {
   })
 }
 
+/**
+ * Looks for a new version now. The room socket calls it when it connects
+ * again: a deploy restarts the server and drops every socket, so a box
+ * (which takes new versions by itself) is up to date within moments,
+ * not an hour later.
+ */
+export function checkForUpdate() {
+  if (!import.meta.env.PROD || !('serviceWorker' in navigator)) return
+  void navigator.serviceWorker
+    .getRegistration()
+    .then((reg) => reg?.update())
+    .catch(() => {})
+}
+
 /** Chromium's install prompt event, which TypeScript's DOM types lack. */
 type InstallPromptEvent = Event & { prompt(): Promise<void>; userChoice: Promise<{ outcome: 'accepted' | 'dismissed' }> }
 
diff --git a/web/src/lib/room-socket.ts b/web/src/lib/room-socket.ts
index 4386268..6303607 100644
--- a/web/src/lib/room-socket.ts
+++ b/web/src/lib/room-socket.ts
@@ -13,6 +13,7 @@ import { gameRoundQuery, gameScoresQuery, type GameRound, type GameScores } from
 import { guestPassQuery, guestsQuery } from './guests'
 import { crown, heartsQuery, nightsQuery, type Hearts, type Night } from './nights'
 import { newer, playbackQuery, type Playback } from './playback'
+import { checkForUpdate } from './pwa'
 import { putQueueGame, queueGamesQuery, type QueueGame } from './queue-games'
 import { addReaction, type Reaction } from './reactions'
 import { leaveRoom, queueQuery, roomsQuery, type QueueSnapshot, type Room } from './room'
@@ -68,6 +69,7 @@ export function useRoomSocket(roomId: string | undefined, { display = false, onS
     let retry: ReturnType<typeof setTimeout> | undefined
     let attempt = 0
     let closed = false
+    let opened = false
     live.set({ roomId, status: 'connecting', members: [] })
 
     const connect = () => {
@@ -93,6 +95,9 @@ export function useRoomSocket(roomId: string | undefined, { display = false, onS
       // as soon as it's connected, and whenever boxd says something new.
       sock.onopen = () => {
         if (reportBox && box.info) sendBoxStatus(sock, box.info)
+        // Back after a drop, maybe a deploy: there may be a new version.
+        if (opened) checkForUpdate()
+        opened = true
       }
       sock.onmessage = (e) => {
         attempt = 0