diff --git a/classes/condition.php b/classes/condition.php
index 473a67f..ad8b838 100644
--- a/classes/condition.php
+++ b/classes/condition.php
@@ -93,6 +93,10 @@ public function is_available($not, \core_availability\info $info, $grabthelot, $
                 $allow = true; 
             }
         }
+
+        if ($not) {
+            $allow = !$allow;
+        }
         return $allow;
     }