diff --git a/test/unit/RequestCanonicalizerTest.php b/test/unit/RequestCanonicalizerTest.php
index 9b7517e..4c1ed58 100644
--- a/test/unit/RequestCanonicalizerTest.php
+++ b/test/unit/RequestCanonicalizerTest.php
@@ -22,7 +22,7 @@ public function  urlEncodeQueryStringShouldReplacePlusSignWithSplace()
     {
         $query = "email=test%2Bbayxd%40gmail.com";
         $expected = "email=test%20bayxd%40gmail.com";
-        $result = RequestCanonicalizer::urlEncodeQueryString($query, "application/x-www-form-urlencoded");
+        $result = RequestCanonicalizer::urlEncodeQueryString($query, "Content-Type: application/x-www-form-urlencoded");
         $this->assertEquals($expected, $result);
     }
 }
\ No newline at end of file