diff --git a/lib/Auth/Source/External.php b/lib/Auth/Source/External.php
index 8bb691f..ff67de8 100755
--- a/lib/Auth/Source/External.php
+++ b/lib/Auth/Source/External.php
@@ -92,8 +92,8 @@ class External extends Source
      */
     public function __construct($info, $config)
     {
-        assert('is_array($info)');
-        assert('is_array($config)');
+        assert(is_array($info));
+        assert(is_array($config));
 
         /* Call the parent constructor first, as required by the interface. */
         parent::__construct($info, $config);
diff --git a/lib/Auth/Source/UserPass.php b/lib/Auth/Source/UserPass.php
index 91b7b89..dbc19c3 100644
--- a/lib/Auth/Source/UserPass.php
+++ b/lib/Auth/Source/UserPass.php
@@ -72,8 +72,8 @@ class UserPass extends UserPassBase
      */
     public function __construct($info, $config)
     {
-        assert('is_array($info)');
-        assert('is_array($config)');
+        assert(is_array($info));
+        assert(is_array($config));
 
         /* Call the parent constructor first, as required by the interface. */
         parent::__construct($info, $config);
@@ -103,8 +103,8 @@ public function __construct($info, $config)
      */
     protected function login($username, $password)
     {
-        assert('is_string($username)');
-        assert('is_string($password)');
+        assert(is_string($username));
+        assert(is_string($password));
 
         $drupalHelper = new DrupalHelper();
         $drupalHelper->bootDrupal($this->config->getDrupalroot());
diff --git a/lib/ConfigHelper.php b/lib/ConfigHelper.php
index 2b46a87..0b72c0c 100644
--- a/lib/ConfigHelper.php
+++ b/lib/ConfigHelper.php
@@ -77,8 +77,8 @@ class ConfigHelper
      */
     public function __construct($config, $location)
     {
-        assert('is_array($config)');
-        assert('is_string($location)');
+        assert(is_array($config));
+        assert(is_string($location));
 
         $this->location = $location;
 
@@ -95,7 +95,7 @@ public function __construct($config, $location)
         $this->cookie_path = Configuration::getInstance()->getBasePath();
         $this->cookie_salt = Config::getSecretSalt();
     }
-    
+
 
     /**
      * Returns debug mode.