diff --git a/src/FuzeWorks/Libraries.php b/src/FuzeWorks/Libraries.php
index 07ab638..ab6dcf6 100644
--- a/src/FuzeWorks/Libraries.php
+++ b/src/FuzeWorks/Libraries.php
@@ -97,7 +97,7 @@ class Libraries
      */
     public function addLibraryClass(string $libraryName, string $libraryClass)
     {
-        if (!class_exists($libraryClass, false))
+        if (!class_exists($libraryClass, true))
             throw new LibraryException("Could not add library class. '" . $libraryClass . "' could not be loaded.", 1);
 
         $this->libraryClasses[strtolower($libraryName)] = $libraryClass;