diff --git a/redisson-tomcat/redisson-tomcat-7/src/main/java/org/redisson/tomcat/RedissonSession.java b/redisson-tomcat/redisson-tomcat-7/src/main/java/org/redisson/tomcat/RedissonSession.java
index f66bc0a04..fc097ac0b 100644
--- a/redisson-tomcat/redisson-tomcat-7/src/main/java/org/redisson/tomcat/RedissonSession.java
+++ b/redisson-tomcat/redisson-tomcat-7/src/main/java/org/redisson/tomcat/RedissonSession.java
@@ -344,7 +344,7 @@ public class RedissonSession extends StandardSession {
             
             if (updateMode == UpdateMode.AFTER_REQUEST) {
                 if (!removedAttributes.isEmpty()) {
-                    topic.publish(new AttributeRemoveMessage(redissonManager.getNodeId(), getId(), removedAttributes));
+                    topic.publish(new AttributeRemoveMessage(redissonManager.getNodeId(), getId(), new HashSet<>(removedAttributes)));
                 }
             }
         }
diff --git a/redisson-tomcat/redisson-tomcat-8/src/main/java/org/redisson/tomcat/RedissonSession.java b/redisson-tomcat/redisson-tomcat-8/src/main/java/org/redisson/tomcat/RedissonSession.java
index f66bc0a04..fc097ac0b 100644
--- a/redisson-tomcat/redisson-tomcat-8/src/main/java/org/redisson/tomcat/RedissonSession.java
+++ b/redisson-tomcat/redisson-tomcat-8/src/main/java/org/redisson/tomcat/RedissonSession.java
@@ -344,7 +344,7 @@ public class RedissonSession extends StandardSession {
             
             if (updateMode == UpdateMode.AFTER_REQUEST) {
                 if (!removedAttributes.isEmpty()) {
-                    topic.publish(new AttributeRemoveMessage(redissonManager.getNodeId(), getId(), removedAttributes));
+                    topic.publish(new AttributeRemoveMessage(redissonManager.getNodeId(), getId(), new HashSet<>(removedAttributes)));
                 }
             }
         }
diff --git a/redisson-tomcat/redisson-tomcat-9/src/main/java/org/redisson/tomcat/RedissonSession.java b/redisson-tomcat/redisson-tomcat-9/src/main/java/org/redisson/tomcat/RedissonSession.java
index ce37167ed..aa0df098b 100644
--- a/redisson-tomcat/redisson-tomcat-9/src/main/java/org/redisson/tomcat/RedissonSession.java
+++ b/redisson-tomcat/redisson-tomcat-9/src/main/java/org/redisson/tomcat/RedissonSession.java
@@ -350,7 +350,7 @@ public class RedissonSession extends StandardSession {
             
             if (updateMode == UpdateMode.AFTER_REQUEST) {
                 if (!removedAttributes.isEmpty()) {
-                    topic.publish(new AttributeRemoveMessage(redissonManager.getNodeId(), getId(), removedAttributes));
+                    topic.publish(new AttributeRemoveMessage(redissonManager.getNodeId(), getId(), new HashSet<>(removedAttributes)));
                 }
             }
         }