diff --git a/src/hnswbuild.c b/src/hnswbuild.c
index 8caf1f3..e1c3bd6 100644
--- a/src/hnswbuild.c
+++ b/src/hnswbuild.c
@@ -378,6 +378,7 @@ BuildCallback(Relation index, CALLBACK_ITEM_POINTER, Datum *values,
 	if (inserted)
 	{
 		element->value = datumTransfer(element->value, false, -1);
+		element->loaded = true;
 		buildstate->elements = lappend(buildstate->elements, element);
 	}
 	else
diff --git a/src/hnswutils.c b/src/hnswutils.c
index 2bb40f3..de816e2 100644
--- a/src/hnswutils.c
+++ b/src/hnswutils.c
@@ -188,6 +188,8 @@ HnswFreeElement(HnswElement element)
 {
 	HnswFreeNeighbors(element);
 	list_free_deep(element->heaptids);
+	if (element->loaded)
+		pfree(DatumGetPointer(element->value));
 	pfree(element);
 }