diff --git a/.travis.yml b/.travis.yml
index 0ddaf9a..7b98679 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,6 +20,9 @@ services:
 
 sudo: false
 
+env:
+  - REDIS_URI=localhost
+
 install:
   - composer install --no-interaction
 
diff --git a/README.md b/README.md
index 2041da0..8acbb4e 100644
--- a/README.md
+++ b/README.md
@@ -264,6 +264,16 @@ To run the test suite, go to the project root and run:
 $ php vendor/bin/phpunit
 ```
 
+The test suite contains both unit tests and functional integration tests.
+The functional tests require access to a running Redis server instance
+and will be skipped by default.
+If you want to also run the functional tests, you need to supply *your* login
+details in an environment variable like this:
+
+```bash
+$ REDIS_URI=localhost:6379 php vendor/bin/phpunit
+```
+
 ## License
 
 MIT
diff --git a/tests/FunctionalTest.php b/tests/FunctionalTest.php
index bf03b94..b7beb6f 100644
--- a/tests/FunctionalTest.php
+++ b/tests/FunctionalTest.php
@@ -14,9 +14,14 @@ class FunctionalTest extends TestCase
 
     public function setUp()
     {
+        $uri = getenv('REDIS_URI');
+        if ($uri === false) {
+            $this->markTestSkipped('No REDIS_URI environment variable given');
+        }
+
         $this->loop = new React\EventLoop\StreamSelectLoop();
         $this->factory = new Factory($this->loop);
-        $this->client = $this->createClient();
+        $this->client = $this->createClient($uri);
     }
 
     public function testPing()
@@ -104,7 +109,7 @@ public function testMonitorPing()
     public function testPubSub()
     {
         $consumer = $this->client;
-        $producer = $this->createClient();
+        $producer = $this->createClient(getenv('REDIS_URI'));
 
         $channel = 'channel:test:' . mt_rand();
 
@@ -157,11 +162,12 @@ public function testInvalidServerRepliesWithDuplicateMessages()
     }
 
     /**
+     * @param string $uri
      * @return Client
      */
-    protected function createClient()
+    protected function createClient($uri)
     {
-        return Block\await($this->factory->createClient(), $this->loop);
+        return Block\await($this->factory->createClient($uri), $this->loop);
     }
 
     protected function createClientResponse($response)