diff --git a/modules/system/ServiceProvider.php b/modules/system/ServiceProvider.php
index 055d89ba5..ae065786a 100644
--- a/modules/system/ServiceProvider.php
+++ b/modules/system/ServiceProvider.php
@@ -9,6 +9,7 @@ use Backend;
 use Request;
 use BackendMenu;
 use BackendAuth;
+use Twig\Extension\SandboxExtension;
 use Twig\Environment as TwigEnvironment;
 use System\Classes\MailManager;
 use System\Classes\ErrorHandler;
@@ -28,7 +29,6 @@ use October\Rain\Support\ModuleServiceProvider;
 use October\Rain\Router\Helper as RouterHelper;
 use Illuminate\Pagination\Paginator;
 use Illuminate\Support\Facades\Schema;
-use Twig\Extension\SandboxExtension;
 
 class ServiceProvider extends ModuleServiceProvider
 {
diff --git a/modules/system/twig/SecurityPolicy.php b/modules/system/twig/SecurityPolicy.php
index 8c49af038..bcbc7a150 100644
--- a/modules/system/twig/SecurityPolicy.php
+++ b/modules/system/twig/SecurityPolicy.php
@@ -10,7 +10,7 @@ use Twig\Sandbox\SecurityNotAllowedPropertyError;
  * SecurityPolicy globally blocks accessibility of certain methods and properties.
  *
  * @package october\system
- * @author Alexey Bobkov, Samuel Georges
+ * @author Alexey Bobkov, Samuel Georges, Luke Towers
  */
 final class SecurityPolicy implements SecurityPolicyInterface
 {
@@ -19,7 +19,7 @@ final class SecurityPolicy implements SecurityPolicyInterface
      */
     protected $blockedMethods = [
         'addDynamicMethod',
-        'addDynamicProperty'
+        'addDynamicProperty',
     ];
 
     /**
@@ -33,13 +33,24 @@ final class SecurityPolicy implements SecurityPolicyInterface
     }
 
     /**
-     * @throws SecurityError
+     * Check the provided arguments against this security policy
+     *
+     * @param array $tags Array of tags to be checked against the policy ['tag', 'tag2', 'etc']
+     * @param array $filters Array of filters to be checked against the policy ['filter', 'filter2', 'etc']
+     * @param array $functions Array of funtions to be checked against the policy ['function', 'function2', 'etc']
+     * @throws SecurityNotAllowedTagError if a given tag is not allowed
+     * @throws SecurityNotAllowedFilterError if a given filter is not allowed
+     * @throws SecurityNotAllowedFunctionError if a given function is not allowed
      */
     public function checkSecurity($tags, $filters, $functions)
     {
     }
 
     /**
+     * Checks if a given property is permitted to be accessed on a given object
+     *
+     * @param object $obj
+     * @param string $property
      * @throws SecurityNotAllowedPropertyError
      */
     public function checkPropertyAllowed($obj, $property)
@@ -47,10 +58,15 @@ final class SecurityPolicy implements SecurityPolicyInterface
     }
 
     /**
+     * Checks if a given method is allowed to be called on a given object
+     *
+     * @param object $obj
+     * @param string $method
      * @throws SecurityNotAllowedMethodError
      */
     public function checkMethodAllowed($obj, $method)
     {
+        // No need to check Twig internal objects
         if ($obj instanceof Template || $obj instanceof Markup) {
             return;
         }