diff --git a/contrib/btree_gist/btree_bit.c b/contrib/btree_gist/btree_bit.c
index 0df2ae20d8b..a8f2636c638 100644
--- a/contrib/btree_gist/btree_bit.c
+++ b/contrib/btree_gist/btree_bit.c
@@ -215,7 +215,7 @@ gbt_bit_ssup_cmp(Datum x, Datum y, SortSupport ssup)
 	Datum		result;
 
 	/* for leaf items we expect lower == upper, so only compare lower */
-	result = DirectFunctionCall2(byteacmp,
+	result = DirectFunctionCall2(bitcmp,
 								 PointerGetDatum(arg1.lower),
 								 PointerGetDatum(arg2.lower));