diff --git a/include/fggl/modules/manager.hpp b/include/fggl/modules/manager.hpp
index 61fa6e05f496db3c726ce1b64e364fb1ea777efb..6279702891a1a9224cfb5645399820b56c91e9b3 100644
--- a/include/fggl/modules/manager.hpp
+++ b/include/fggl/modules/manager.hpp
@@ -203,6 +203,7 @@ namespace fggl::modules {
 			}
 
 			void resolve() {
+				assert( !m_locked );
 				if (!buildGraph()) {
 					return;
 				}