diff --git a/examples/src/Entities/ClientEntity.php b/examples/src/Entities/ClientEntity.php
index 2427b4e7..822a3f64 100644
--- a/examples/src/Entities/ClientEntity.php
+++ b/examples/src/Entities/ClientEntity.php
@@ -82,4 +82,4 @@ class ClientEntity implements ClientEntityInterface
     {
         return $this->secret !== null;
     }
-}
\ No newline at end of file
+}
diff --git a/examples/src/Entities/ScopeEntity.php b/examples/src/Entities/ScopeEntity.php
index 35611da2..23d12a44 100644
--- a/examples/src/Entities/ScopeEntity.php
+++ b/examples/src/Entities/ScopeEntity.php
@@ -9,8 +9,8 @@ class ScopeEntity implements ScopeEntityInterface
 {
     use EntityTrait;
 
-    function jsonSerialize()
+    public function jsonSerialize()
     {
         return $this->getIdentifier();
     }
-}
\ No newline at end of file
+}
diff --git a/examples/src/Repositories/ClientRepository.php b/examples/src/Repositories/ClientRepository.php
index 5a5a32f7..4727871b 100644
--- a/examples/src/Repositories/ClientRepository.php
+++ b/examples/src/Repositories/ClientRepository.php
@@ -22,7 +22,7 @@ class ClientRepository implements ClientRepositoryInterface
 
         // Check if client is registered
         if (array_key_exists($clientIdentifier, $clients) === false) {
-            return null;
+            return;
         }
 
         $client = new ClientEntity();
diff --git a/examples/src/Repositories/ScopeRepository.php b/examples/src/Repositories/ScopeRepository.php
index f9b50dbb..014ca3dd 100644
--- a/examples/src/Repositories/ScopeRepository.php
+++ b/examples/src/Repositories/ScopeRepository.php
@@ -22,7 +22,7 @@ class ScopeRepository implements ScopeRepositoryInterface
         ];
 
         if (array_key_exists($scopeIdentifier, $scopes) === false) {
-            return null;
+            return;
         }
 
         $scope = new ScopeEntity();