diff --git a/src/Service/StateBasedAuthenticationService.php b/src/Service/StateBasedAuthenticationService.php
index 4fdfc9b..828b2f2 100644
--- a/src/Service/StateBasedAuthenticationService.php
+++ b/src/Service/StateBasedAuthenticationService.php
@@ -52,7 +52,7 @@ public function authenticationRequired()
     public function authenticate()
     {
         if (!$this->stateHandler->isRequestTypeAuthentication()) {
-            $this->logger->critical('Current request does not need a authentication');
+            $this->logger->critical('Current request does not need an authentication');
             throw RuntimeException::shouldNotAuthenticate();
         }
         $this->logger->notice('Application authenticates the user');
@@ -62,7 +62,7 @@ public function authenticate()
     public function isAuthenticated()
     {
         if (!$this->stateHandler->isRequestTypeAuthentication()) {
-            $this->logger->critical('Current request does not need a authentication');
+            $this->logger->critical('Current request does not need an authentication');
             throw RuntimeException::shouldNotAuthenticate();
         }
         return $this->stateHandler->isAuthenticated();
diff --git a/tests/Service/StateBasedAuthenticationServiceTest.php b/tests/Service/StateBasedAuthenticationServiceTest.php
index e6e064b..cfa209d 100644
--- a/tests/Service/StateBasedAuthenticationServiceTest.php
+++ b/tests/Service/StateBasedAuthenticationServiceTest.php
@@ -30,7 +30,7 @@ public function testIsAuthenticateThrowWhenInInvalidAuthenticationState()
         $stateHandler->shouldReceive('isRequestTypeAuthentication')->andReturnFalse();
         $router = \Mockery::mock(RouterInterface::class);
         $logger = \Mockery::mock(LoggerInterface::class);
-        $logger->shouldReceive('critical')->with('Current request does not need a authentication');
+        $logger->shouldReceive('critical')->with('Current request does not need an authentication');
         $registrationService = new StateBasedAuthenticationService(
             $stateHandler,
             $router,