diff --git a/Domain/Entry.php b/Domain/Entry.php
index 55c4b37..7797cf1 100644
--- a/Domain/Entry.php
+++ b/Domain/Entry.php
@@ -181,7 +181,9 @@ public function serialize()
         return serialize(array(
             $this->mask,
             $this->id,
-            $this->securityIdentity,
+            // clone due to the unserialize issue in php 5.4-5.6
+            // when Acl has few FieldEntry objects with the same SecurityIdentityInterface instance
+            clone $this->securityIdentity,
             $this->strategy,
             $this->auditFailure,
             $this->auditSuccess,
diff --git a/Tests/Domain/FieldEntryTest.php b/Tests/Domain/FieldEntryTest.php
index 735e2e8..e189931 100644
--- a/Tests/Domain/FieldEntryTest.php
+++ b/Tests/Domain/FieldEntryTest.php
@@ -40,6 +40,40 @@ public function testSerializeUnserialize()
         $this->assertEquals($ace->isAuditFailure(), $uAce->isAuditFailure());
     }
 
+    /**
+     * Test that two FieldEntry objects correctly serialized and unserialized
+     */
+    public function testSerializeUnserializeMoreAceWithSameSecurityIdentity()
+    {
+        $sid = $this->getSid();
+
+        $aceFirst = $this->getAce(null, $sid);
+        $aceSecond = $this->getAce(null, $sid);
+
+        // as used in DoctrineAclCache::putInCache (line 142)
+        $serialized = serialize(
+            array( // Acl:serialize (line 260)
+                [  // classFieldAces
+                    'fieldOne' => [$aceFirst], 
+                    'fieldTwo' => [$aceSecond],
+                ]
+            )
+        );
+
+        $unserialized = unserialize($serialized);
+        $uAceFirst  = $unserialized[0]['fieldOne'][0];
+        $uAceSecond = $unserialized[0]['fieldTwo'][0];
+
+        $this->assertInstanceOf(
+            'Symfony\Component\Security\Acl\Model\SecurityIdentityInterface',
+            $uAceFirst->getSecurityIdentity()
+        );
+        $this->assertInstanceOf(
+            'Symfony\Component\Security\Acl\Model\SecurityIdentityInterface',
+            $uAceSecond->getSecurityIdentity()
+        );
+    }
+
     protected function getAce($acl = null, $sid = null)
     {
         if (null === $acl) {