diff --git a/src/Http/PipedriveClient.php b/src/Http/PipedriveClient.php
index ae00bff..3fe129d 100644
--- a/src/Http/PipedriveClient.php
+++ b/src/Http/PipedriveClient.php
@@ -29,9 +29,10 @@ class PipedriveClient implements Client
      * GuzzleClient constructor.
      *
      * @param $url
-     * @param $token
+     * @param $credentials
+     * @param array $requestOptions
      */
-    public function __construct($url, $credentials)
+    public function __construct($url, $credentials, $requestOptions = [])
     {
         list($headers, $query) = [[], []];
 
@@ -42,14 +43,16 @@ public function __construct($url, $credentials)
             $query['api_token'] = $credentials;
         }
 
-        $this->client = new GuzzleClient(
-            [
-                'base_uri'        => $url,
-                'allow_redirects' => false,
-                'headers'         => $headers,
-                'query'           => $query
-            ]
-        );
+        $config = [
+            'base_uri'        => $url,
+            'allow_redirects' => false,
+            'headers'         => $headers,
+            'query'           => $query
+        ];
+
+        $config = array_merge($config, $requestOptions);
+
+        $this->client = new GuzzleClient($config);
     }
 
     /**
@@ -70,7 +73,7 @@ public static function OAuth($url, $storage, $pipedrive)
 
         $token->refreshIfNeeded($pipedrive);
 
-        return new self($url, $token);
+        return new self($url, $token, $pipedrive->getRequestOptions());
     }
 
     /**
diff --git a/src/Http/PipedriveClient4.php b/src/Http/PipedriveClient4.php
index 9f4198b..2e81164 100644
--- a/src/Http/PipedriveClient4.php
+++ b/src/Http/PipedriveClient4.php
@@ -33,15 +33,20 @@ class PipedriveClient4 implements Client
      *
      * @param $url
      * @param $token
+     * @param array $requestOptions
      */
-    public function __construct($url, $token)
+    public function __construct($url, $token, $requestOptions = [])
     {
+        $defaults = [
+            'query' => ['api_token' => $token]
+        ];
+
+        $defaults = array_merge($defaults, $requestOptions);
+
         $this->client = new GuzzleClient(
             [
                 'base_url' => $url,
-                'defaults' => [
-                    'query' => ['api_token' => $token],
-                ]
+                'defaults' => $defaults
             ]
         );
     }
diff --git a/src/Pipedrive.php b/src/Pipedrive.php
index dc28e93..a24ce97 100644
--- a/src/Pipedrive.php
+++ b/src/Pipedrive.php
@@ -171,6 +171,13 @@ class Pipedrive
      */
     protected $storage;
 
+    /**
+     * A list of request options.
+     *
+     * @var array
+     */
+    protected $requestOptions;
+
     public function isOauth()
     {
         return $this->isOauth;
@@ -179,15 +186,20 @@ public function isOauth()
     /**
      * Pipedrive constructor.
      *
-     * @param $token
+     * @param string $token
+     * @param string $uri
+     * @param int $guzzleVersion
+     * @param array $requestOptions
      */
-    public function __construct($token = '', $uri = 'https://api.pipedrive.com/v1/', $guzzleVersion = 6)
+    public function __construct($token = '', $uri = 'https://api.pipedrive.com/v1/', $guzzleVersion = 6, $requestOptions = [])
     {
         $this->token = $token;
         $this->baseURI = $uri;
         $this->guzzleVersion = $guzzleVersion;
 
         $this->isOauth = false;
+
+        $this->requestOptions = is_array($requestOptions) ? $requestOptions : [];
     }
 
     /**
@@ -198,9 +210,10 @@ public function __construct($token = '', $uri = 'https://api.pipedrive.com/v1/',
      */
     public static function OAuth($config)
     {
-        $guzzleVersion = isset($config['guzzleVersion']) ? $config['guzzleVersion'] : 6;
+        $guzzleVersion  = isset($config['guzzleVersion']) ? $config['guzzleVersion'] : 6;
+        $requestOptions = isset($config['requestOptions']) ? $config['requestOptions'] : [];
 
-        $new = new self('oauth', 'https://api.pipedrive.com/', $guzzleVersion);
+        $new = new self('oauth', 'https://api.pipedrive.com/', $guzzleVersion, $requestOptions);
 
         $new->isOauth = true;
 
@@ -352,9 +365,9 @@ protected function getClient()
         if ($this->guzzleVersion >= 6) {
             return $this->isOauth()
                 ? PipedriveClient::OAuth($this->getBaseURI(), $this->storage, $this)
-                : new PipedriveClient($this->getBaseURI(), $this->token);
+                : new PipedriveClient($this->getBaseURI(), $this->token, $this->requestOptions);
         } else {
-            return new PipedriveClient4($this->getBaseURI(), $this->token);
+            return new PipedriveClient4($this->getBaseURI(), $this->token, $this->requestOptions);
         }
     }
 
@@ -388,6 +401,14 @@ public function setToken($token)
         $this->token = $token;
     }
 
+    /**
+     * Get a list of request options.
+     */
+    public function getRequestOptions()
+    {
+        return $this->requestOptions;
+    }
+
     /**
      * Any reading will return a resource.
      *
diff --git a/src/PipedriveToken.php b/src/PipedriveToken.php
index 1c25dda..01377cc 100644
--- a/src/PipedriveToken.php
+++ b/src/PipedriveToken.php
@@ -90,12 +90,16 @@ public function refreshIfNeeded($pipedrive)
             return;
         }
 
-        $client = new GuzzleClient([
+        $config = [
             'auth' => [
                 $pipedrive->getClientId(),
                 $pipedrive->getClientSecret()
             ]
-        ]);
+        ];
+
+        $config = array_merge($config, $pipedrive->getRequestOptions());
+
+        $client = new GuzzleClient($config);
 
         $response = $client->request('POST', 'https://oauth.pipedrive.com/oauth/token', [
             'form_params' => [