diff --git a/autoload.php b/autoload.php
deleted file mode 100644
index b12b45e43..000000000
--- a/autoload.php
+++ /dev/null
@@ -1,34 +0,0 @@
-<?php
-/*
- * Copyright 2014 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-function oauth2client_php_autoload($className)
-{
-    $classPath = explode('_', $className);
-    if ('Google' != $classPath[0]) {
-        return;
-    }
-    if (count($classPath) > 3) {
-        // Maximum class file path depth in this project is 3.
-        $classPath = array_slice($classPath, 0, 3);
-    }
-    $filePath = dirname(__FILE__) . '/src/' . implode('/', $classPath) . '.php';
-    if (file_exists($filePath)) {
-        require_once $filePath;
-    }
-}
-
-spl_autoload_register('oauth2client_php_autoload');
diff --git a/src/Auth/Credentials/ComputeCredentials.php b/src/Auth/Credentials/ComputeCredentials.php
index a6c8105f4..76bbca95d 100644
--- a/src/Auth/Credentials/ComputeCredentials.php
+++ b/src/Auth/Credentials/ComputeCredentials.php
@@ -117,14 +117,19 @@ class ComputeCredentials implements
     private $jwtClient;
 
     /**
-     * @param array        $options
-     * @param array|string $options.scope                  the scope of the access request,
-     *                                                     expressed either as an array or as a space-delimited string.
-     * @param string       $options.targetAudience         The audience for the ID token.
-     * @param string       $options.quotaProject           Specifies a project to bill for access
-     *                                                     charges associated with the request.
-     * @param string       $options.serviceAccountIdentity [optional] Specify a service
-     *                                                     account identity name to use instead of "default".
+     * @param array                  $options
+     * @param array|string           $options.scope                  the scope of the access request,
+     *                                                               expressed either as an array or as a space-delimited string.
+     * @param string                 $options.targetAudience         The audience for the ID token.
+     * @param string                 $options.quotaProject           Specifies a project to bill for access
+     *                                                               charges associated with the request.
+     * @param string                 $options.serviceAccountIdentity [optional] Specify a service
+     *                                                               account identity name to use instead of "default".
+     * @param HttpClientInterface    $options.httpClient
+     * @param JwtClientInterface     $options.jwtClient
+     * @param CacheItemPoolInterface $options.cache
+     * @param string                 $options.cachePrefix
+     * @param int                    $options.cacheLifetime
      */
     public function __construct(array $options = [])
     {
diff --git a/src/Auth/Credentials/ServiceAccountCredentials.php b/src/Auth/Credentials/ServiceAccountCredentials.php
index 4f57a0225..d01b63557 100644
--- a/src/Auth/Credentials/ServiceAccountCredentials.php
+++ b/src/Auth/Credentials/ServiceAccountCredentials.php
@@ -100,15 +100,19 @@ class ServiceAccountCredentials implements
     /**
      * Create a new ServiceAccountCredentials.
      *
-     * @param array|string $jsonKey                JSON credential file path or JSON
-     *                                             credentials in associative array
-     * @param array        $options
-     * @param array|string $options.scope          the scope of the access request, expressed
-     *                                             as an array or as a space-delimited string
-     * @param string       $options.subject        an email address account to impersonate, in
-     *                                             situations when the service account has been delegated domain
-     *                                             wide access
-     * @param string       $options.targetAudience The audience for the ID token.
+     * @param array|string           $jsonKey                JSON credential file path or JSON
+     *                                                       credentials in associative array
+     * @param array                  $options
+     * @param array|string           $options.scope          the scope of the access request, expressed
+     *                                                       as an array or as a space-delimited string
+     * @param string                 $options.subject        an email address account to impersonate, in
+     *                                                       situations when the service account has been delegated domain
+     *                                                       wide access
+     * @param string                 $options.targetAudience The audience for the ID token.
+     * @param HttpClientInterface    $options.httpClient
+     * @param CacheItemPoolInterface $options.cache
+     * @param string                 $options.cachePrefix
+     * @param int                    $options.cacheLifetime
      */
     public function __construct($jsonKey, array $options = [])
     {
diff --git a/src/Auth/Credentials/ServiceAccountJwtAccessCredentials.php b/src/Auth/Credentials/ServiceAccountJwtAccessCredentials.php
index a04cc1256..06b7b2aa5 100644
--- a/src/Auth/Credentials/ServiceAccountJwtAccessCredentials.php
+++ b/src/Auth/Credentials/ServiceAccountJwtAccessCredentials.php
@@ -58,9 +58,14 @@ class ServiceAccountJwtAccessCredentials implements
     /**
      * Create a new ServiceAccountJwtAccessCredentials.
      *
-     * @param array|string $jsonKey JSON credential file path or JSON credentials
-     *                              as an associative array
-     * @param array $options
+     * @param array|string           $jsonKey               JSON credential file path or JSON credentials
+     *                                                      as an associative array
+     * @param array                  $options
+     * @param string                 $options.audience
+     * @param HttpClientInterface    $options.httpClient
+     * @param CacheItemPoolInterface $options.cache
+     * @param string                 $options.cachePrefix
+     * @param int                    $options.cacheLifetime
      */
     public function __construct($jsonKey, array $options = [])
     {
diff --git a/src/Auth/Credentials/UserRefreshCredentials.php b/src/Auth/Credentials/UserRefreshCredentials.php
index 4de2403ee..a92b7edaf 100644
--- a/src/Auth/Credentials/UserRefreshCredentials.php
+++ b/src/Auth/Credentials/UserRefreshCredentials.php
@@ -51,9 +51,14 @@ class UserRefreshCredentials implements CredentialsInterface
     /**
      * Create a new UserRefreshCredentials.
      *
-     * @param array        $jsonKey JSON credential as an associative array
-     * @param array|string $scope   the scope of the access request, expressed
-     *                              either as an Array or as a space-delimited String
+     * @param array                  $jsonKey               JSON credential as an associative array
+     * @param array                  $options
+     * @param array                  $options.scope         the scope of the access request, expressed
+     *                                                      either as an Array or as a space-delimited String
+     * @param HttpClientInterface    $options.httpClient
+     * @param CacheItemPoolInterface $options.cache
+     * @param string                 $options.cachePrefix
+     * @param int                    $options.cacheLifetime
      */
     public function __construct($jsonKey, array $options = [])
     {
diff --git a/src/Auth/GoogleAuth.php b/src/Auth/GoogleAuth.php
index c3c94b310..58cf1127a 100644
--- a/src/Auth/GoogleAuth.php
+++ b/src/Auth/GoogleAuth.php
@@ -96,7 +96,6 @@ class GoogleAuth
      *                                                      provided if you have one already available for use.
      * @param int                    $options.cacheLifetime
      * @param string                 $options.cachePrefix
-     *                                                      }
      */
     public function __construct(array $options = [])
     {
diff --git a/tests/Auth/Credentials/CredentialsTraitTest.php b/tests/Auth/Credentials/CredentialsTraitTest.php
index ff8c172e7..7f1dba3b3 100644
--- a/tests/Auth/Credentials/CredentialsTraitTest.php
+++ b/tests/Auth/Credentials/CredentialsTraitTest.php
@@ -342,7 +342,7 @@ private function fetchAuthTokenNoCache(): array
         return $this->token;
     }
 
-    private function getCacheKey()
+    private function getCacheKey(): string
     {
         return $this->key;
     }