diff --git a/Tests/Transport/Serialization/PhpSerializerTest.php b/Tests/Transport/Serialization/PhpSerializerTest.php
index 6439873f..5076577b 100644
--- a/Tests/Transport/Serialization/PhpSerializerTest.php
+++ b/Tests/Transport/Serialization/PhpSerializerTest.php
@@ -44,7 +44,7 @@ public function testDecodingFailsWithMissingBodyKey()
     public function testDecodingFailsWithBadFormat()
     {
         $this->expectException(MessageDecodingFailedException::class);
-        $this->expectExceptionMessageRegExp('/Could not decode/');
+        $this->expectExceptionMessageMatches('/Could not decode/');
 
         $serializer = new PhpSerializer();
 
@@ -56,7 +56,7 @@ public function testDecodingFailsWithBadFormat()
     public function testDecodingFailsWithBadClass()
     {
         $this->expectException(MessageDecodingFailedException::class);
-        $this->expectExceptionMessageRegExp('/class "ReceivedSt0mp" not found/');
+        $this->expectExceptionMessageMatches('/class "ReceivedSt0mp" not found/');
 
         $serializer = new PhpSerializer();