diff --git a/dlm/pom.xml b/dlm/pom.xml
index abba79fad..d70c39d1a 100644
--- a/dlm/pom.xml
+++ b/dlm/pom.xml
@@ -29,11 +29,6 @@
             <groupId>com.hazelcast</groupId>
             <artifactId>hazelcast</artifactId>
         </dependency>
-        <dependency>
-            <groupId>com.hazelcast</groupId>
-            <artifactId>hazelcast-client</artifactId>
-            <scope>test</scope>
-        </dependency>
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
diff --git a/dlm/src/main/java/org/dcache/nfs/v4/nlm/DistributedLockManager.java b/dlm/src/main/java/org/dcache/nfs/v4/nlm/DistributedLockManager.java
index 8a5d06b97..9fc01bf4f 100644
--- a/dlm/src/main/java/org/dcache/nfs/v4/nlm/DistributedLockManager.java
+++ b/dlm/src/main/java/org/dcache/nfs/v4/nlm/DistributedLockManager.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017 - 2020 Deutsches Elektronen-Synchroton,
+ * Copyright (c) 2017 - 2022 Deutsches Elektronen-Synchroton,
  * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY
  *
  * This library is free software; you can redistribute it and/or modify
@@ -20,8 +20,7 @@
 package org.dcache.nfs.v4.nlm;
 
 import com.hazelcast.core.HazelcastInstance;
-import com.hazelcast.core.MultiMap;
-
+import com.hazelcast.multimap.MultiMap;
 import java.util.Base64;
 import java.util.Collection;
 import java.util.concurrent.TimeUnit;
diff --git a/dlm/src/test/java/org/dcache/nfs/v4/nlm/DistributedLockManagerTest.java b/dlm/src/test/java/org/dcache/nfs/v4/nlm/DistributedLockManagerTest.java
index 37c5e091d..7bde3a241 100644
--- a/dlm/src/test/java/org/dcache/nfs/v4/nlm/DistributedLockManagerTest.java
+++ b/dlm/src/test/java/org/dcache/nfs/v4/nlm/DistributedLockManagerTest.java
@@ -33,7 +33,7 @@ public void setUp() throws Exception {
                 "127.0.0.1:" + hzSerrver.getCluster().getLocalMember().getAddress().getPort())
         );
 
-        config.getGroupConfig().setName(hzSerrver.getConfig().getGroupConfig().getName());
+        config.setClusterName(hzSerrver.getConfig().getClusterName());
         hzClient = HazelcastClient.newHazelcastClient(config);
         lm1 = new DistributedLockManager(hzClient, "distributed-byte-range-lock");
         lm2 = new DistributedLockManager(hzClient, "distributed-byte-range-lock");
diff --git a/dlm/src/test/resources/hazelcast.xml b/dlm/src/test/resources/hazelcast.xml
index 5a0a04280..ea4c02683 100644
--- a/dlm/src/test/resources/hazelcast.xml
+++ b/dlm/src/test/resources/hazelcast.xml
@@ -1,10 +1,8 @@
-<hazelcast xsi:schemaLocation="http://www.hazelcast.com/schema/config hazelcast-config-3.10.xsd"
+<hazelcast xsi:schemaLocation="http://www.hazelcast.com/schema/config hazelcast-config-4.1.xsd"
            xmlns="http://www.hazelcast.com/schema/config"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 
-    <group>
-        <name>nfs-dlm-test</name>
-    </group>
+    <cluster-name>nfs-dlm-test</cluster-name>
 
     <properties>
         <property name="hazelcast.logging.type">slf4j</property>
diff --git a/pom.xml b/pom.xml
index 4099228e4..8116a133d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -199,12 +199,7 @@
           <dependency>
               <groupId>com.hazelcast</groupId>
               <artifactId>hazelcast</artifactId>
-              <version>3.9.2</version>
-          </dependency>
-          <dependency>
-              <groupId>com.hazelcast</groupId>
-              <artifactId>hazelcast-client</artifactId>
-              <version>3.9.2</version>
+              <version>4.1.8</version>
           </dependency>
           <dependency>
               <groupId>com.sleepycat</groupId>