diff --git a/savanna/plugins/vanilla/config_helper.py b/savanna/plugins/vanilla/config_helper.py
index 030e138e..5dab8ad6 100644
--- a/savanna/plugins/vanilla/config_helper.py
+++ b/savanna/plugins/vanilla/config_helper.py
@@ -21,6 +21,7 @@ from savanna.plugins.vanilla import mysql_helper as m_h
 from savanna.plugins.vanilla import oozie_helper as o_h
 from savanna.swift import swift_helper as swift
 from savanna.topology import topology_helper as topology
+from savanna.utils import types as types
 from savanna.utils import xmlutils as x
 
 
@@ -120,7 +121,7 @@ def _initialise_configs():
                     if cfg.default_value in ["true", "false"]:
                         cfg.config_type = "bool"
                         cfg.default_value = (cfg.default_value == 'true')
-                    if str(cfg.default_value).isdigit():
+                    elif types.is_int(cfg.default_value):
                         cfg.config_type = "int"
                         cfg.default_value = int(cfg.default_value)
                     if config['name'] in CLUSTER_WIDE_CONFS:
diff --git a/savanna/tests/unit/utils/test_types.py b/savanna/tests/unit/utils/test_types.py
new file mode 100644
index 00000000..294f88b1
--- /dev/null
+++ b/savanna/tests/unit/utils/test_types.py
@@ -0,0 +1,29 @@
+# Copyright (c) 2013 Mirantis Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest2
+
+from savanna.utils import types as types
+
+
+class TypesTestCase(unittest2.TestCase):
+
+    def test_is_int(self):
+        self.assertTrue(types.is_int('1'))
+        self.assertTrue(types.is_int('0'))
+        self.assertTrue(types.is_int('-1'))
+        self.assertFalse(types.is_int('1.1'))
+        self.assertFalse(types.is_int('ab'))
+        self.assertFalse(types.is_int(''))
diff --git a/savanna/utils/types.py b/savanna/utils/types.py
index b1464c83..182eb37a 100644
--- a/savanna/utils/types.py
+++ b/savanna/utils/types.py
@@ -84,3 +84,11 @@ class FrozenDict(dict):
 class FrozenClassError(Exception):
     def __init__(self, instance):
         self.message = "Class %s is immutable!" % type(instance).__name__
+
+
+def is_int(s):
+    try:
+        int(s)
+        return True
+    except Exception:
+        return False