diff --git a/src/hnswinsert.c b/src/hnswinsert.c
index d11e3eb..7fe836d 100644
--- a/src/hnswinsert.c
+++ b/src/hnswinsert.c
@@ -54,7 +54,7 @@ HnswFreeOffset(Relation index, Buffer buf, Page page, HnswElement element, Size
 			ItemId		itemid;
 
 			if (!BlockNumberIsValid(*firstFreePage))
-				*firstFreePage = BufferGetBlockNumber(buf);
+				*firstFreePage = neighborPage;
 
 			if (neighborPage == BufferGetBlockNumber(buf))
 			{