diff --git a/lib/acme/certs.js b/lib/acme/certs.js
index efa7a688..844348f3 100644
--- a/lib/acme/certs.js
+++ b/lib/acme/certs.js
@@ -9,7 +9,6 @@ const AcmeChallenge = require('./acme-challenge');
 const pkg = require('../../package.json');
 const { normalizeDomain } = require('../tools');
 const Lock = require('ioredfour');
-const util = require('util');
 const log = require('npmlog');
 const { Resolver } = require('dns').promises;
 const resolver = new Resolver();
@@ -187,8 +186,8 @@ const acquireCert = async (domain, acmeOptions, certificateData, certHandler) =>
             redis: db.redis,
             namespace: 'acme'
         });
-        getLock = util.promisify(lock.waitAcquireLock.bind(lock));
-        releaseLock = util.promisify(lock.releaseLock.bind(lock));
+        getLock = (...args) => lock.waitAcquireLock(...args);
+        releaseLock = (...args) => lock.releaseLock(...args);
     }
 
     let lock = await getLock(domainOpLockKey, 10 * 60 * 1000, 3 * 60 * 1000);
diff --git a/lib/consts.js b/lib/consts.js
index 56f67690..98c7213d 100644
--- a/lib/consts.js
+++ b/lib/consts.js
@@ -84,6 +84,9 @@ module.exports = {
 
     TASK_LOCK_INTERVAL: 1 * 3600 * 1000,
 
+    // unlock pending tasks in every 2 minutes
+    TASK_RELEASE_DELAYED_INTERVAL: 2 * 60 * 1000,
+
     // renewal interval, must be lower than TASK_LOCK_INTERVAL
     TASK_UPDATE_INTERVAL: 10 * 60 * 1000,
 
diff --git a/package.json b/package.json
index 05dc9261..d3906bee 100644
--- a/package.json
+++ b/package.json
@@ -54,7 +54,7 @@
         "html-to-text": "8.0.0",
         "humanname": "0.2.2",
         "iconv-lite": "0.6.3",
-        "ioredfour": "1.0.2-ioredis-03",
+        "ioredfour": "1.1.0-ioredis-05",
         "ioredis": "4.27.6",
         "ipaddr": "0.1.0",
         "ipaddr.js": "2.0.1",
diff --git a/tasks.js b/tasks.js
index 1ea9f1af..ad30fa4d 100644
--- a/tasks.js
+++ b/tasks.js
@@ -448,25 +448,21 @@ function timer(ttl) {
 }
 
 async function runTasks() {
-    // first release expired tasks
-    try {
-        await taskHandler.releasePending();
-    } catch (err) {
-        log.error('Tasks', 'Failed releasing expired tasks. error=%s', err.message);
-        taskTimeout = setTimeout(runTasks, consts.TASK_STARTUP_INTERVAL);
-        await timer(consts.TASK_STARTUP_INTERVAL);
-        return runTasks();
-    }
+    let pendingCheckTime = 0;
 
-    let startTime = Date.now();
     let done = false;
     log.verbose('Tasks', 'Starting task poll loop');
     while (!done) {
-        if (Date.now() - startTime > 3600 * 1000) {
-            // Once in a while break the loop, so that pending tasks can be unlocked
-            done = true;
-            log.verbose('Tasks', 'Breaking task poll loop');
-            break;
+        if (Date.now() - pendingCheckTime > consts.TASK_RELEASE_DELAYED_INTERVAL) {
+            // Once in a while release pending tasks
+            try {
+                await taskHandler.releasePending();
+            } catch (err) {
+                log.error('Tasks', 'Failed releasing expired tasks. error=%s', err.message);
+                await timer(consts.TASK_IDLE_INTERVAL);
+            } finally {
+                pendingCheckTime = Date.now();
+            }
         }
 
         try {