diff --git a/src/main/java/org/redisson/RedissonSet.java b/src/main/java/org/redisson/RedissonSet.java
index 176cb3931..0b927aa78 100644
--- a/src/main/java/org/redisson/RedissonSet.java
+++ b/src/main/java/org/redisson/RedissonSet.java
@@ -17,6 +17,7 @@ package org.redisson;
 
 import java.util.Collection;
 import java.util.Iterator;
+import java.util.NoSuchElementException;
 
 import org.redisson.connection.ConnectionManager;
 import org.redisson.core.RSet;
@@ -69,10 +70,44 @@ public class RedissonSet<V> extends RedissonObject implements RSet<V> {
         RedisConnection<Object, Object> connection = connectionManager.connection();
         try {
             // TODO use SSCAN in case of usage Redis 2.8
-            return (Iterator<V>) connection.smembers(getName()).iterator();
+            final Iterator<V> iter = (Iterator<V>) connection.smembers(getName()).iterator();
+            return new Iterator<V>() {
+
+                private boolean removeExecuted;
+                private V value;
+
+                @Override
+                public boolean hasNext() {
+                    return iter.hasNext();
+                }
+
+                @Override
+                public V next() {
+                    if (!hasNext()) {
+                        throw new NoSuchElementException("No such element at index");
+                    }
+
+                    value = iter.next();
+                    removeExecuted = false;
+                    return value;
+                }
+
+                @Override
+                public void remove() {
+                    if (removeExecuted) {
+                        throw new IllegalStateException("Element been already deleted");
+                    }
+
+                    iter.remove();
+                    RedissonSet.this.remove(value);
+                    removeExecuted = true;
+                }
+
+            };
         } finally {
             connectionManager.release(connection);
         }
+
     }
 
     @Override
@@ -138,10 +173,9 @@ public class RedissonSet<V> extends RedissonObject implements RSet<V> {
     @Override
     public boolean retainAll(Collection<?> c) {
         boolean changed = false;
-        for (Iterator<V> iterator = iterator(); iterator.hasNext();) {
-            V object = iterator.next();
+        for (Object object : this) {
             if (!c.contains(object)) {
-                iterator.remove();
+                remove(object);
                 changed = true;
             }
         }
diff --git a/src/main/java/org/redisson/connection/ConnectionManager.java b/src/main/java/org/redisson/connection/ConnectionManager.java
index 4bee65261..a9f42b5cb 100644
--- a/src/main/java/org/redisson/connection/ConnectionManager.java
+++ b/src/main/java/org/redisson/connection/ConnectionManager.java
@@ -162,8 +162,8 @@ public class ConnectionManager {
     }
 
     public void release(RedisConnection сonnection) {
-        activeConnections.release();
         connections.add(сonnection);
+        activeConnections.release();
     }
 
     public void shutdown() {
diff --git a/src/test/java/org/redisson/RedissonSetTest.java b/src/test/java/org/redisson/RedissonSetTest.java
index 33c7250d5..dfc16f181 100644
--- a/src/test/java/org/redisson/RedissonSetTest.java
+++ b/src/test/java/org/redisson/RedissonSetTest.java
@@ -10,6 +10,20 @@ import org.junit.Test;
 
 public class RedissonSetTest extends BaseTest {
 
+    @Test
+    public void testRetainAll() {
+        Redisson redisson = Redisson.create();
+        Set<Integer> set = redisson.getSet("set");
+        for (int i = 0; i < 200; i++) {
+            set.add(i);
+        }
+
+        Assert.assertTrue(set.retainAll(Arrays.asList(1, 2)));
+        Assert.assertEquals(2, set.size());
+
+        clear(set, redisson);
+    }
+
     @Test
     public void testContainsAll() {
         Redisson redisson = Redisson.create();