diff --git a/prop_instance_merger.cpp b/prop_instance_merger.cpp
index ba3cef4..93c747d 100644
--- a/prop_instance_merger.cpp
+++ b/prop_instance_merger.cpp
@@ -124,7 +124,7 @@ Ref<PropInstanceJob> PropInstanceMerger::get_job() {
 void PropInstanceMerger::set_job(const Ref<PropInstanceJob> &job) {
 	_job = job;
 
-	if (is_inside_tree()) {
+	if (_job.is_valid() && is_inside_tree()) {
 		_job->prop_instance_enter_tree();
 	}
 }