diff --git a/lib/Cake/Network/Http/Auth/Oauth.php b/lib/Cake/Network/Http/Auth/Oauth.php
index 9e7668fea47..d95fd55e70d 100644
--- a/lib/Cake/Network/Http/Auth/Oauth.php
+++ b/lib/Cake/Network/Http/Auth/Oauth.php
@@ -229,7 +229,7 @@ protected function _normalizedParams($request, $oauthValues) {
  * @return string
  */
 	protected function _buildAuth($data) {
-		$out = 'Oauth ';
+		$out = 'OAuth ';
 		$params = [];
 		foreach ($data as $key => $value) {
 			$params[] = $key . '="' . $this->_encode($value) . '"';
diff --git a/lib/Cake/Test/TestCase/Network/Http/Auth/OauthTest.php b/lib/Cake/Test/TestCase/Network/Http/Auth/OauthTest.php
index 4fd55709854..00104b38c48 100644
--- a/lib/Cake/Test/TestCase/Network/Http/Auth/OauthTest.php
+++ b/lib/Cake/Test/TestCase/Network/Http/Auth/OauthTest.php
@@ -56,7 +56,7 @@ public function testPlainTextSigning() {
 		$auth->authentication($request, $creds);
 
 		$result = $request->header('Authorization');
-		$this->assertContains('Oauth', $result);
+		$this->assertContains('OAuth', $result);
 		$this->assertContains('oauth_version="1.0"', $result);
 		$this->assertContains('oauth_token="a%20token%20value"', $result);
 		$this->assertContains('oauth_consumer_key="a%20key"', $result);