diff --git a/redisson-tomcat/redisson-tomcat-6/src/main/java/org/redisson/tomcat/RedissonSession.java b/redisson-tomcat/redisson-tomcat-6/src/main/java/org/redisson/tomcat/RedissonSession.java
index e58ae13a3..28ca6f373 100644
--- a/redisson-tomcat/redisson-tomcat-6/src/main/java/org/redisson/tomcat/RedissonSession.java
+++ b/redisson-tomcat/redisson-tomcat-6/src/main/java/org/redisson/tomcat/RedissonSession.java
@@ -167,8 +167,10 @@ public class RedissonSession extends StandardSession {
         newMap.put("session:isValid", isValid);
         newMap.put("session:isNew", isNew);
         
-        for (Entry<String, Object> entry : attrs.entrySet()) {
-            newMap.put(entry.getKey(), entry.getValue());
+        if (attrs != null) {
+            for (Entry<String, Object> entry : attrs.entrySet()) {
+                newMap.put(entry.getKey(), entry.getValue());
+            }
         }
         
         map.putAll(newMap);
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 91bcacb54..ef5d6b6fb 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
@@ -171,8 +171,10 @@ public class RedissonSession extends StandardSession {
         newMap.put("session:isValid", isValid);
         newMap.put("session:isNew", isNew);
         
-        for (Entry<String, Object> entry : attrs.entrySet()) {
-            newMap.put(entry.getKey(), entry.getValue());
+        if (attrs != null) {
+            for (Entry<String, Object> entry : attrs.entrySet()) {
+                newMap.put(entry.getKey(), entry.getValue());
+            }
         }
         
         map.putAll(newMap);
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 7d37c4d31..a88e29561 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
@@ -172,8 +172,10 @@ public class RedissonSession extends StandardSession {
         newMap.put("session:isValid", isValid);
         newMap.put("session:isNew", isNew);
         
-        for (Entry<String, Object> entry : attrs.entrySet()) {
-            newMap.put(entry.getKey(), entry.getValue());
+        if (attrs != null) {
+            for (Entry<String, Object> entry : attrs.entrySet()) {
+                newMap.put(entry.getKey(), entry.getValue());
+            }
         }
         
         map.putAll(newMap);