diff --git a/src/Cookies.php b/src/Cookies.php
index 044d438..9be7453 100644
--- a/src/Cookies.php
+++ b/src/Cookies.php
@@ -148,7 +148,7 @@ protected function toHeader(string $name, array $properties): string
                 $timestamp = (int) $properties['expires'];
             }
             if ($timestamp && $timestamp !== 0) {
-                $result .= '; expires=' . gmdate('D, d-M-Y H:i:s e', $timestamp);
+                $result .= '; expires=' . gmdate('D, d M Y H:i:s', $timestamp) . ' GMT';
             }
         }
 
diff --git a/tests/CookiesTest.php b/tests/CookiesTest.php
index d365ac1..4a9d1a0 100644
--- a/tests/CookiesTest.php
+++ b/tests/CookiesTest.php
@@ -242,7 +242,7 @@ public function testToHeader()
             ]
         ];
         $time = time();
-        $formattedDate = gmdate('D, d-M-Y H:i:s e', $time);
+        $formattedDate = gmdate('D, d M Y H:i:s \G\M\T', $time);
         $propertiesComplex = [
             'name' => 'test_complex',
             'properties' => [
@@ -257,7 +257,7 @@ public function testToHeader()
             ]
         ];
         $stringDate = '2016-01-01 12:00:00';
-        $formattedStringDate = gmdate('D, d-M-Y H:i:s e', strtotime($stringDate));
+        $formattedStringDate = gmdate('D, d M Y H:i:s \G\M\T', strtotime($stringDate));
         $propertiesStringDate = [
             'name' => 'test_date',
             'properties' => [