diff --git a/src/EventListener/AuthorizationRequestUserResolvingListenerTrait.php b/src/EventListener/AuthorizationRequestUserResolvingListenerTrait.php
index 8e95d4f2..f9d4861d 100644
--- a/src/EventListener/AuthorizationRequestUserResolvingListenerTrait.php
+++ b/src/EventListener/AuthorizationRequestUserResolvingListenerTrait.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 namespace League\Bundle\OAuth2ServerBundle\EventListener;
 
 use League\Bundle\OAuth2ServerBundle\Event\AuthorizationRequestResolveEvent;
diff --git a/src/Model/AccessTokenInterface.php b/src/Model/AccessTokenInterface.php
index f1056830..dca46d1a 100644
--- a/src/Model/AccessTokenInterface.php
+++ b/src/Model/AccessTokenInterface.php
@@ -4,15 +4,13 @@
 
 namespace League\Bundle\OAuth2ServerBundle\Model;
 
-use DateTimeInterface;
-
 interface AccessTokenInterface
 {
     public function __toString(): string;
 
     public function getIdentifier(): string;
 
-    public function getExpiry(): DateTimeInterface;
+    public function getExpiry(): \DateTimeInterface;
 
     public function getUserIdentifier(): ?string;
 
diff --git a/src/Model/AuthorizationCodeInterface.php b/src/Model/AuthorizationCodeInterface.php
index fc8abe86..83c37987 100644
--- a/src/Model/AuthorizationCodeInterface.php
+++ b/src/Model/AuthorizationCodeInterface.php
@@ -4,15 +4,13 @@
 
 namespace League\Bundle\OAuth2ServerBundle\Model;
 
-use DateTimeInterface;
-
 interface AuthorizationCodeInterface
 {
     public function __toString(): string;
 
     public function getIdentifier(): string;
 
-    public function getExpiryDateTime(): DateTimeInterface;
+    public function getExpiryDateTime(): \DateTimeInterface;
 
     public function getUserIdentifier(): ?string;
 
diff --git a/src/Model/RefreshTokenInterface.php b/src/Model/RefreshTokenInterface.php
index 46ead423..865c5a5a 100644
--- a/src/Model/RefreshTokenInterface.php
+++ b/src/Model/RefreshTokenInterface.php
@@ -4,15 +4,13 @@
 
 namespace League\Bundle\OAuth2ServerBundle\Model;
 
-use DateTimeInterface;
-
 interface RefreshTokenInterface
 {
     public function __toString(): string;
 
     public function getIdentifier(): string;
 
-    public function getExpiry(): DateTimeInterface;
+    public function getExpiry(): \DateTimeInterface;
 
     public function getAccessToken(): ?AccessTokenInterface;