diff --git a/src/backend/access/gist/gistscan.c b/src/backend/access/gist/gistscan.c
index 12c74b982ca..2105ed604be 100644
--- a/src/backend/access/gist/gistscan.c
+++ b/src/backend/access/gist/gistscan.c
@@ -17,6 +17,7 @@
 #include "access/gist_private.h"
 #include "access/gistscan.h"
 #include "access/relscan.h"
+#include "utils/builtins.h"
 #include "utils/lsyscache.h"
 #include "utils/memutils.h"
 #include "utils/rel.h"
@@ -36,8 +37,10 @@ pairingheap_GISTSearchItem_cmp(const pairingheap_node *a, const pairingheap_node
 	/* Order according to distance comparison */
 	for (i = 0; i < scan->numberOfOrderBys; i++)
 	{
-		if (sa->distances[i] != sb->distances[i])
-			return (sa->distances[i] < sb->distances[i]) ? 1 : -1;
+		int			cmp = -float8_cmp_internal(sa->distances[i], sb->distances[i]);
+
+		if (cmp != 0)
+			return cmp;
 	}
 
 	/* Heap items go before inner pages, to ensure a depth-first search */