diff --git a/.travis.yml b/.travis.yml
index 2c7bef4..30f5601 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,4 +11,5 @@ matrix:
     - php: hhvm
 
 before_script:
+  - sh -c 'if [ "$TRAVIS_PHP_VERSION" != "hhvm" ]; then echo "session.serialize_handler = php" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi;'
   - composer install --dev --prefer-source
diff --git a/src/Ratchet/Session/SessionProvider.php b/src/Ratchet/Session/SessionProvider.php
index 8aefc96..a8495b2 100644
--- a/src/Ratchet/Session/SessionProvider.php
+++ b/src/Ratchet/Session/SessionProvider.php
@@ -56,14 +56,7 @@ class SessionProvider implements MessageComponentInterface, WsServerInterface {
         $this->setOptions($options);
 
         if (null === $serializer) {
-            // Temporarily fixing HHVM issue w/ reading ini values
-            $handler_name = ini_get('session.serialize_handler');
-            if ('' === $handler_name) {
-                trigger_error('ini value session.seralize_handler was empty, assuming "php" - tmp hack/fix, bad things might happen', E_USER_WARNING);
-                $handler_name = 'php';
-            }
-
-            $serialClass = __NAMESPACE__ . "\\Serialize\\{$this->toClassCase($handler_name)}Handler"; // awesome/terrible hack, eh?
+            $serialClass = __NAMESPACE__ . "\\Serialize\\{$this->toClassCase(ini_get('session.serialize_handler'))}Handler"; // awesome/terrible hack, eh?
             if (!class_exists($serialClass)) {
                 throw new \RuntimeException('Unable to parse session serialize handler');
             }
diff --git a/src/Ratchet/Wamp/TopicManager.php b/src/Ratchet/Wamp/TopicManager.php
index bceee73..a69e315 100644
--- a/src/Ratchet/Wamp/TopicManager.php
+++ b/src/Ratchet/Wamp/TopicManager.php
@@ -77,8 +77,11 @@ class TopicManager implements WsServerInterface, WampServerInterface {
     public function onClose(ConnectionInterface $conn) {
         $this->app->onClose($conn);
 
-        foreach ($this->topicLookup as $topic) {
-            $topic->remove($conn);
+        foreach ($this->topicLookup as $topic => $storage) {
+            $storage->remove($conn);
+            if (0 === $storage->count()) {
+                unset($this->topicLookup[$topic]);
+            }
         }
     }
 
diff --git a/tests/unit/Wamp/TopicManagerTest.php b/tests/unit/Wamp/TopicManagerTest.php
index 0c31d9a..7439064 100644
--- a/tests/unit/Wamp/TopicManagerTest.php
+++ b/tests/unit/Wamp/TopicManagerTest.php
@@ -166,12 +166,19 @@ class TopicManagerTest extends \PHPUnit_Framework_TestCase {
         $method = $class->getMethod('getTopic');
         $method->setAccessible(true);
 
+        $attribute = $class->getProperty('topicLookup');
+        $attribute->setAccessible(true);
+
         $topic = $method->invokeArgs($this->mngr, array($name));
 
+        $this->assertCount(1, $attribute->getValue($this->mngr));
+
         $this->mngr->onSubscribe($this->conn, $name);
         $this->mngr->onClose($this->conn);
 
         $this->assertFalse($topic->has($this->conn));
+
+        $this->assertCount(0, $attribute->getValue($this->mngr));
     }
 
     public function testOnErrorBubbles() {