diff --git a/contrib/pg_upgrade/info.c b/contrib/pg_upgrade/info.c
index 55489ac..3b31622 100644
--- a/contrib/pg_upgrade/info.c
+++ b/contrib/pg_upgrade/info.c
@@ -242,7 +242,7 @@ get_db_infos(migratorContext *ctx, DbInfoArr *dbinfs_arr, Cluster whichCluster)
 
 	for (tupnum = 0; tupnum < ntups; tupnum++)
 	{
-		dbinfos[tupnum].db_oid = str2uint(PQgetvalue(res, tupnum, i_oid));
+		dbinfos[tupnum].db_oid = atooid(PQgetvalue(res, tupnum, i_oid));
 
 		snprintf(dbinfos[tupnum].db_name, sizeof(dbinfos[tupnum].db_name), "%s",
 				 PQgetvalue(res, tupnum, i_datname));
@@ -360,7 +360,7 @@ get_rel_infos(migratorContext *ctx, const DbInfo *dbinfo,
 		RelInfo    *curr = &relinfos[num_rels++];
 		const char *tblspace;
 
-		curr->reloid = str2uint(PQgetvalue(res, relnum, i_oid));
+		curr->reloid = atooid(PQgetvalue(res, relnum, i_oid));
 
 		nspname = PQgetvalue(res, relnum, i_nspname);
 		strlcpy(curr->nspname, nspname, sizeof(curr->nspname));
@@ -368,8 +368,8 @@ get_rel_infos(migratorContext *ctx, const DbInfo *dbinfo,
 		relname = PQgetvalue(res, relnum, i_relname);
 		strlcpy(curr->relname, relname, sizeof(curr->relname));
 
-		curr->relfilenode = str2uint(PQgetvalue(res, relnum, i_relfilenode));
-		curr->toastrelid = str2uint(PQgetvalue(res, relnum, i_reltoastrelid));
+		curr->relfilenode = atooid(PQgetvalue(res, relnum, i_relfilenode));
+		curr->toastrelid = atooid(PQgetvalue(res, relnum, i_reltoastrelid));
 
 		tblspace = PQgetvalue(res, relnum, i_spclocation);
 		/* if no table tablespace, use the database tablespace */
diff --git a/contrib/pg_upgrade/pg_upgrade.h b/contrib/pg_upgrade/pg_upgrade.h
index 296b80f..73070c6 100644
--- a/contrib/pg_upgrade/pg_upgrade.h
+++ b/contrib/pg_upgrade/pg_upgrade.h
@@ -52,6 +52,8 @@
 
 #define CLUSTERNAME(cluster)	((cluster) == CLUSTER_OLD ? "old" : "new")
 
+#define atooid(x)  ((Oid) strtoul((x), NULL, 10))
+
 /* OID system catalog preservation added during PG 9.0 development */
 #define TABLE_SPACE_SUBDIRS 201001111
 
diff --git a/contrib/pg_upgrade/relfilenode.c b/contrib/pg_upgrade/relfilenode.c
index dd605bb..3a11bab 100644
--- a/contrib/pg_upgrade/relfilenode.c
+++ b/contrib/pg_upgrade/relfilenode.c
@@ -94,9 +94,9 @@ get_pg_database_relfilenode(migratorContext *ctx, Cluster whichCluster)
 
 	i_relfile = PQfnumber(res, "relfilenode");
 	if (whichCluster == CLUSTER_OLD)
-		ctx->old.pg_database_oid = str2uint(PQgetvalue(res, 0, i_relfile));
+		ctx->old.pg_database_oid = atooid(PQgetvalue(res, 0, i_relfile));
 	else
-		ctx->new.pg_database_oid = str2uint(PQgetvalue(res, 0, i_relfile));
+		ctx->new.pg_database_oid = atooid(PQgetvalue(res, 0, i_relfile));
 
 	PQclear(res);
 	PQfinish(conn);