diff --git a/playwright/pages/client.ts b/playwright/pages/client.ts
index abd487988b..7d62f42ae0 100644
--- a/playwright/pages/client.ts
+++ b/playwright/pages/client.ts
@@ -294,6 +294,8 @@ export class Client {
      *
      * This is often useful after joining a room, when we need to wait for the sync loop to catch up.
      *
+     * Times out with an error after 1 second.
+     *
      * @param roomId - ID of the room to check
      * @param membership - required membership.
      */
@@ -310,7 +312,15 @@ export class Client {
                 };
                 if (isReady()) return;
 
-                return new Promise<void>((resolve) => {
+                const timeoutPromise = new Promise((resolve) => setTimeout(resolve, 1000)).then(() => {
+                    const room = cli.getRoom(roomId);
+                    const myMembership = room?.getMyMembership();
+                    throw new Error(
+                        `Timeout waiting for room ${roomId} membership (now '${myMembership}', wanted '${membership}')`,
+                    );
+                });
+
+                const readyPromise = new Promise<void>((resolve) => {
                     async function onEvent() {
                         if (isReady()) {
                             cli.removeListener(window.matrixcs.ClientEvent.Event, onEvent);
@@ -320,6 +330,8 @@ export class Client {
 
                     cli.on(window.matrixcs.ClientEvent.Event, onEvent);
                 });
+
+                return Promise.race([timeoutPromise, readyPromise]);
             },
             { roomId, membership },
         );