diff --git a/dynsupdate/client.py b/dynsupdate/client.py
index 468e581..e89e97f 100644
--- a/dynsupdate/client.py
+++ b/dynsupdate/client.py
@@ -72,7 +72,7 @@ def simple_ip_fetch(url, extract_fun=lambda x: x.strip(), timeout=5):
             # Limit response size
             data = resp.read(MAX_RESPONSE_DATA)
     except (URLError, socket.error) as e:
-        logger.warn('couldn\'t fetch url "{0}" with timeout {1:d}'
+        logger.warn('couldn\'t fetch url "{0}" with timeout {1:.4g}'
                     .format(url, timeout))
         return None
     else:
@@ -468,6 +468,30 @@ def parse(input_str):
     return parse
 
 
+def integer_range(min=None, max=None):
+
+    def validate_int(value):
+        try:
+            res = int(value)
+        except ValueError:
+            raise argparse.ArgumentTypeError('Invalid integer "%s"' % value)
+        else:
+            if min is not None and res < min:
+                raise argparse.ArgumentTypeError(
+                    'Value "{val}" is smaller than "{min}"'
+                    .format(val=res, min=min)
+                )
+            elif max is not None and res > max:
+                raise argparse.ArgumentTypeError(
+                    'Value "{val}" is bigger than "{max}"'
+                    .format(val=res, max=min)
+                )
+
+            return res
+
+    return validate_int
+
+
 class Program(object):
 
     COMMANDS = {
@@ -558,14 +582,16 @@ def ip_fun(cls, tries=5, timeout=5, types=None, services=None):
 
     @classmethod
     def ip_arguments(cls, parser):
+        tries_type = integer_range(min=1)
         types_type = comma_separated_list(SimpleIpGetter.SERVICE_TYPES)
         services_type = comma_separated_list(SimpleIpGetter.SERVICE_NAMES)
-        parser.add_argument('-n', '--tries', dest="tries", type=int, default=5)
+        parser.add_argument('-n', '--tries', dest="tries", type=tries_type,
+                            default=5)
         parser.add_argument('-t', '--types', dest="types", type=types_type,
                             default=None)
         parser.add_argument('--services', dest="services", type=services_type,
                             default=None)
-        parser.add_argument('--timeout', dest="timeout", type=int, default=5)
+        parser.add_argument('--timeout', dest="timeout", type=float, default=5)
 
     @classmethod
     def build_parser(cls):
diff --git a/tests/test_cli_iterface.py b/tests/test_cli_iterface.py
index c18798d..8369b22 100644
--- a/tests/test_cli_iterface.py
+++ b/tests/test_cli_iterface.py
@@ -15,6 +15,10 @@
 """
 
 
+class ExitException(Exception):
+    pass
+
+
 class CliParseTest(TestCase):
 
     def test_comma_separated_list(self):
@@ -27,6 +31,13 @@ def test_comma_separated_list(self):
         self.assertRaises(argparse.ArgumentTypeError, my_types, "http,bad")
         # TODO: Maybe tests arguments in uppercase to
 
+    def test_validate_int(self):
+        positive_int = client.integer_range(min=0)
+        self.assertRaises(argparse.ArgumentTypeError, positive_int, "bad")
+        self.assertRaises(argparse.ArgumentTypeError, positive_int, "-2")
+        self.assertRaises(argparse.ArgumentTypeError, positive_int, "-1")
+        self.assertEqual(positive_int("0"), 0)
+
 
 class CliIterfaceTest(TestCase):
 
@@ -50,6 +61,17 @@ def patch_urlopen(self):
         self.addCleanup(urlopen_patch.stop)
 
     def patch_argparse(self):
+        self.arg_exit_mock = mock.Mock(spec=[])
+        self.arg_error_mock = mock.Mock(spec=[])
+        self.arg_exit_mock.side_effect = ExitException
+        self.arg_error_mock.side_effect = ExitException
+        argparse_patch = mock.patch.multiple(
+            'argparse.ArgumentParser',
+            exit=self.arg_exit_mock,
+            error=self.arg_error_mock
+        )
+        argparse_patch.start()
+        self.addCleanup(argparse_patch.stop)
 
         filetype_patch = mock.patch('argparse.FileType')
         self.filetype_mock = filetype_patch.start()
@@ -122,6 +144,16 @@ def test_interface_checkip(self):
         ret_value = self.stdout_mock.getvalue()
         self.assertIn('127.0.0.1', ret_value)
 
+    def test_interface_checkip_bad_num(self):
+        self.urlopen_mock.side_effect = mock.mock_open(read_data="127.0.0.1\n")
+        self.assertEqual(argparse.ArgumentParser.exit, self.arg_exit_mock)
+        prog = client.Program()
+        with self.assertRaises(ExitException):
+            prog.run("checkip -n -2".split(), log=False)
+
+        with self.assertRaises(ExitException):
+            prog.run("checkip -n 0".split(), log=False)
+
     def test_interface_update(self):
         response_mock = mock.mock_open(read_data="127.0.0.6\n")
         self.urlopen_mock.side_effect = response_mock