diff --git a/main.cpp b/main.cpp
index 41a161d..2734dcb 100644
--- a/main.cpp
+++ b/main.cpp
@@ -252,7 +252,7 @@ void GUDButtonListener::onButton1MouseClick(BaseButtonInstance* button)
 			std::vector<Instance*> newinst;
 			for(size_t i = 0; i < selectedInstances.size(); i++)
 			{
-				Instance* inst = ((PhysicalInstance*)selectedInstances.at(i))->clone();
+				Instance* inst = selectedInstances.at(i)->clone();
 				newinst.push_back(inst);
 				inst->setParent(selectedInstances.at(i)->getParent());
 			}