diff --git a/contrib/pgrowlocks/pgrowlocks.c b/contrib/pgrowlocks/pgrowlocks.c
index 075d781..23ec02a 100644
--- a/contrib/pgrowlocks/pgrowlocks.c
+++ b/contrib/pgrowlocks/pgrowlocks.c
@@ -106,7 +106,7 @@ pgrowlocks(PG_FUNCTION_ARGS)
 			aclcheck_error(aclresult, ACL_KIND_CLASS,
 						   RelationGetRelationName(rel));
 
-		scan = heap_beginscan(rel, SnapshotNow, 0, NULL);
+		scan = heap_beginscan(rel, SnapshotSelf, 0, NULL);
 		mydata = palloc(sizeof(*mydata));
 		mydata->rel = rel;
 		mydata->scan = scan;
diff --git a/contrib/pgstattuple/pgstattuple.c b/contrib/pgstattuple/pgstattuple.c
index 7f41ec3..d2667db 100644
--- a/contrib/pgstattuple/pgstattuple.c
+++ b/contrib/pgstattuple/pgstattuple.c
@@ -296,7 +296,7 @@ pgstat_heap(Relation rel, FunctionCallInfo fcinfo)
 		/* must hold a buffer lock to call HeapTupleSatisfiesVisibility */
 		LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
 
-		if (HeapTupleSatisfiesVisibility(tuple, SnapshotNow, scan->rs_cbuf))
+		if (HeapTupleSatisfiesVisibility(tuple, SnapshotSelf, scan->rs_cbuf))
 		{
 			stat.tuple_len += tuple->t_len;
 			stat.tuple_count++;
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index da66f34..649afa1 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4991,7 +4991,7 @@ get_actual_variable_range(PlannerInfo *root, VariableStatData *vardata,
 			/* If min is requested ... */
 			if (min)
 			{
-				index_scan = index_beginscan(heapRel, indexRel, SnapshotNow,
+				index_scan = index_beginscan(heapRel, indexRel, SnapshotSelf,
 											 1, 0);
 				index_rescan(index_scan, scankeys, 1, NULL, 0);
 
@@ -5023,7 +5023,7 @@ get_actual_variable_range(PlannerInfo *root, VariableStatData *vardata,
 			/* If max is requested, and we didn't find the index is empty */
 			if (max && have_data)
 			{
-				index_scan = index_beginscan(heapRel, indexRel, SnapshotNow,
+				index_scan = index_beginscan(heapRel, indexRel, SnapshotSelf,
 											 1, 0);
 				index_rescan(index_scan, scankeys, 1, NULL, 0);