diff --git a/src/SlackDriver.php b/src/SlackDriver.php
index 1b28b7d..751653e 100644
--- a/src/SlackDriver.php
+++ b/src/SlackDriver.php
@@ -225,9 +225,9 @@ public function buildServicePayload($message, $matchingMessage, $additionalParam
     public function sendPayload($payload)
     {
         if ($this->resultType == self::RESULT_TOKEN) {
-            return $this->http->post('https://slack.com/api/chat.postMessage', [], $payload);
+            return $this->http->post($this->config['base_url'] . 'chat.postMessage', [], $payload);
         } elseif ($this->resultType == self::RESULT_DIALOG) {
-            return $this->http->post('https://slack.com/api/dialog.open', [], $payload);
+            return $this->http->post($this->config['base_url'] . 'dialog.open', [], $payload);
         }
 
         return JsonResponse::create($payload)->send();
@@ -387,7 +387,7 @@ public function sendRequest($endpoint, array $parameters, IncomingMessage $match
             'token' => $this->config->get('token'),
         ], $parameters);
 
-        return $this->http->post('https://slack.com/api/'.$endpoint, [], $parameters);
+        return $this->http->post($this->config['base_url'] . $endpoint, [], $parameters);
     }
 
     /**
@@ -407,7 +407,7 @@ public function verifyRequest(Request $request)
      */
     public function getBotUserId()
     {
-        $botUserIdRequest = $this->http->post('https://slack.com/api/auth.test', [], [
+        $botUserIdRequest = $this->http->post($this->config['base_url'] . 'auth.test', [], [
             'token' => $this->config->get('token'),
         ]);
         $botUserIdPayload = new ParameterBag((array) json_decode($botUserIdRequest->getContent(), true));
@@ -423,7 +423,7 @@ public function getBotUserId()
      */
     private function getBotId()
     {
-        $botUserRequest = $this->http->post('https://slack.com/api/users.info', [], [
+        $botUserRequest = $this->http->post($this->config['base_url'] . 'users.info', [], [
             'user' => $this->botUserID,
             'token' => $this->config->get('token'),
         ]);
diff --git a/stubs/slack.php b/stubs/slack.php
index 445b645..4e2272e 100644
--- a/stubs/slack.php
+++ b/stubs/slack.php
@@ -11,5 +11,15 @@
     |
     */
     'token' => env('SLACK_TOKEN'),
+    
+    /*
+    |--------------------------------------------------------------------------
+    | Slack API base url
+    |--------------------------------------------------------------------------
+    |
+    | Your Slack API base url. Useful if you're using Mattermost,
+    |
+    */
+    'base_url' => env('SLACK_BASE_URL', 'https://slack.com/api/'),
 
 ];
diff --git a/tests/SlackDriverTest.php b/tests/SlackDriverTest.php
index 1fde918..7d22a16 100644
--- a/tests/SlackDriverTest.php
+++ b/tests/SlackDriverTest.php
@@ -32,7 +32,7 @@ private function getDriver($responseData, $htmlInterface = null)
             $htmlInterface = m::mock(Curl::class);
         }
 
-        $slackConfig = ['token' => 'Foo'];
+        $slackConfig = ['token' => 'Foo', 'base_url' => 'https://slack.com/api/'];
         $response = new Response('{"ok": true,"url": "https:\/\/myteam.slack.com\/","team": "My Team","user": "cal","team_id": "T12345","user_id": "U0X12345"}');
 
         $htmlInterface->shouldReceive('post')
@@ -227,6 +227,7 @@ public function it_returns_the_user_object()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -438,6 +439,7 @@ public function it_can_reply_string_messages()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -475,6 +477,7 @@ public function it_can_reply_message_objects()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -513,6 +516,7 @@ public function it_can_reply_message_objects_with_image()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -594,6 +598,7 @@ public function it_can_reply_questions_with_additional_button_parameters()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -636,6 +641,7 @@ public function it_can_reply_questions()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -678,6 +684,7 @@ public function it_can_reply_questions_with_menus()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -720,6 +727,7 @@ public function it_can_reply_with_additional_parameters()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -770,6 +778,7 @@ public function it_can_reply_in_threads()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $html);
 
@@ -803,6 +812,7 @@ public function it_is_configured()
         $driver = new SlackDriver($request, [
             'slack' => [
                 'token' => 'Foo',
+                'base_url' => 'https://slack.com/api/'
             ],
         ], $htmlInterface);