diff --git a/prop_instance.cpp b/prop_instance.cpp
index 301560c..48e8fd7 100644
--- a/prop_instance.cpp
+++ b/prop_instance.cpp
@@ -54,6 +54,7 @@ void PropInstance::build() {
 }
 
 void PropInstance::queue_build() {
+	_build_queued = true;
 }
 
 void PropInstance::build_finished() {