diff --git a/app/scodoc/sco_groups.py b/app/scodoc/sco_groups.py
index 87d50e3f..b06a8e46 100644
--- a/app/scodoc/sco_groups.py
+++ b/app/scodoc/sco_groups.py
@@ -89,8 +89,6 @@ group_list = groupEditor.list
 
 def get_group(group_id: int):
     """Returns group object, with partition"""
-    if not isinstance(group_id, int):
-        raise ValueError("invalid group_id (%s)" % group_id)
     r = ndb.SimpleDictFetch(
         """SELECT gd.id AS group_id, gd.*, p.id AS partition_id, p.*
         FROM group_descr gd, partition p
diff --git a/sco_version.py b/sco_version.py
index 39b1b340..3c171d1f 100644
--- a/sco_version.py
+++ b/sco_version.py
@@ -1,7 +1,7 @@
 # -*- mode: python -*-
 # -*- coding: utf-8 -*-
 
-SCOVERSION = "9.1.30"
+SCOVERSION = "9.1.31"
 
 SCONAME = "ScoDoc"