diff --git a/src/AuthenticationService.php b/src/AuthenticationService.php
index 44dd6bf8..b25c126f 100644
--- a/src/AuthenticationService.php
+++ b/src/AuthenticationService.php
@@ -247,9 +247,7 @@ public function persistIdentity(ServerRequestInterface $request, ResponseInterfa
             }
         }
 
-        if (!($identity instanceof IdentityInterface)) {
-            $identity = $this->buildIdentity($identity);
-        }
+        $identity = $this->buildIdentity($identity);
 
         return [
             'request' => $request->withAttribute($this->getConfig('identityAttribute'), $identity),
diff --git a/tests/TestCase/AuthenticationServiceTest.php b/tests/TestCase/AuthenticationServiceTest.php
index 8f1a21d3..15379e24 100644
--- a/tests/TestCase/AuthenticationServiceTest.php
+++ b/tests/TestCase/AuthenticationServiceTest.php
@@ -396,13 +396,13 @@ public function testPersistIdentityInterface()
     {
         $request = new ServerRequest();
         $response = new Response();
-        $identity = $this->createMock(IdentityInterface::class);
+        $identity = new ArrayObject();
 
         $service = new AuthenticationService();
 
         $result = $service->persistIdentity($request, $response, $identity);
 
-        $this->assertSame($identity, $result['request']->getAttribute('identity'));
+        $this->assertInstanceOf(IdentityInterface::class, $result['request']->getAttribute('identity'));
     }
 
     /**