diff --git a/lib/api-functions.ts b/lib/api-functions.ts
index a5d5e88..898fbec 100644
--- a/lib/api-functions.ts
+++ b/lib/api-functions.ts
@@ -39,6 +39,7 @@ import {
 } from "./ui/db";
 import * as common from "./util";
 import * as cache from "./cache";
+import { lockExists } from "./lock";
 import {
   getRevision,
   getConfig,
@@ -211,8 +212,7 @@ export async function awaitSessionStart(
   );
   const li = (device["_lastInform"] as Date).getTime();
   if (li > lastInform) return true;
-  const token = await cache.get(`cwmp_session_${deviceId}`);
-  if (token) return true;
+  if (await lockExists(`cwmp_session_${deviceId}`)) return true;
   if (timeout < 500) return false;
   await new Promise((resolve) => setTimeout(resolve, 500));
   timeout -= Date.now() - now;
@@ -224,8 +224,7 @@ export async function awaitSessionEnd(
   timeout: number
 ): Promise<boolean> {
   const now = Date.now();
-  const token = await cache.get(`cwmp_session_${deviceId}`);
-  if (!token) return true;
+  if (!(await lockExists(`cwmp_session_${deviceId}`))) return true;
   if (timeout < 500) return false;
   await new Promise((resolve) => setTimeout(resolve, 500));
   timeout -= Date.now() - now;
diff --git a/lib/local-cache.ts b/lib/local-cache.ts
index 3b6bb59..640cf6c 100644
--- a/lib/local-cache.ts
+++ b/lib/local-cache.ts
@@ -67,7 +67,7 @@ export class LocalCache<T> {
       return;
     }
 
-    const lockToken = await acquireLock(this.cacheKey + "_lock", 5000);
+    const lockToken = await acquireLock(this.cacheKey, 5000);
 
     const [hash, snapshot] = await this.callback();
 
@@ -84,7 +84,7 @@ export class LocalCache<T> {
 
     if (lockToken) {
       if (hash !== dbHash) await set(this.cacheKey, hash, 300);
-      await releaseLock(this.cacheKey + "_lock", lockToken);
+      await releaseLock(this.cacheKey, lockToken);
     }
 
     this.nextRefresh = now + (REFRESH - (now % REFRESH));
diff --git a/lib/lock.ts b/lib/lock.ts
index d2eac0e..623a294 100644
--- a/lib/lock.ts
+++ b/lib/lock.ts
@@ -43,3 +43,8 @@ export async function releaseLock(
   });
   if (res.deletedCount !== 1) throw new Error("Lock expired");
 }
+
+export async function lockExists(lockName: string): Promise<boolean> {
+  const res = await collections.locks.findOne({ _id: lockName });
+  return res != null;
+}