diff --git a/classes/Engine.php b/classes/Engine.php
index 396251d..29830c1 100644
--- a/classes/Engine.php
+++ b/classes/Engine.php
@@ -142,12 +142,21 @@ class Engine implements RequestHandlerInterface {
      */
     private function executeInvokableClass(RequestInterface $request, $args = null) {
         if (is_array($args) && count($args) > 0) {
+            // Explicit arguments take precedence
             $input = $args;
-        } else {
+        } elseif ($request->getMethod() == 'GET') {
+            // Handle GET requests only if class allows it
+            if ($this->reader->getFirstValueBool($this->object, 'phpmae:allowsGETRequests'))
+                $input = $request->getQueryParams();
+            else
+                return (new Response(405));
+        } elseif ($request->getMethod() == 'POST') {
+            // POST is always allowed
             $input = $request->getParsedBody();
             if (!is_array($input))
-                $input = [];    
-        }
+                $input = [];
+        } else
+            return (new Response(405));
 
         set_time_limit($this->container->has('execution_time_limit')
             ? $this->container->get('execution_time_limit') : self::CLASS_TIME_LIMIT);