diff --git a/src/hnswutils.c b/src/hnswutils.c
index 9122b34..50e3676 100644
--- a/src/hnswutils.c
+++ b/src/hnswutils.c
@@ -769,7 +769,11 @@ SelectNeighbors(List *c, int m, int lc, FmgrInfo *procinfo, Oid collation, HnswE
 
 		w = list_delete_last(w);
 
-		/* r and wd will be the same as previous calls until new element */
+		/*
+		 * r and wd will be the same as previous calls until the new element,
+		 * so can skip distance calculations for as many elements as there is
+		 * state for
+		 */
 		if (mustCalculate)
 			closer = CheckElementCloser(e, r, lc, procinfo, collation);
 		else if (e->element == e2->neighbors[lc].firstPruned)