diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index dabcbb0736..878fcc2236 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -11938,7 +11938,7 @@ check_recovery_target_xid(char **newval, void **extra, GucSource source)
 		TransactionId *myextra;
 
 		errno = 0;
-		xid = (TransactionId) strtoul(*newval, NULL, 0);
+		xid = (TransactionId) pg_strtouint64(*newval, NULL, 0);
 		if (errno == EINVAL || errno == ERANGE)
 			return false;
 
diff --git a/src/test/recovery/t/003_recovery_targets.pl b/src/test/recovery/t/003_recovery_targets.pl
index cc701c5539..dd8e1cc47c 100644
--- a/src/test/recovery/t/003_recovery_targets.pl
+++ b/src/test/recovery/t/003_recovery_targets.pl
@@ -50,6 +50,10 @@ sub test_recovery_standby
 my $node_primary = get_new_node('primary');
 $node_primary->init(has_archiving => 1, allows_streaming => 1);
 
+# Bump the transaction ID epoch.  This is useful to stress the portability
+# of recovery_target_xid parsing.
+system_or_bail('pg_resetwal', '--epoch', '1', $node_primary->data_dir);
+
 # Start it
 $node_primary->start;