diff --git a/neutronclient/neutron/v2_0/tag.py b/neutronclient/neutron/v2_0/tag.py
index 4582716..ff59b74 100644
--- a/neutronclient/neutron/v2_0/tag.py
+++ b/neutronclient/neutron/v2_0/tag.py
@@ -50,6 +50,9 @@ class AddTag(neutronv20.NeutronCommand):
 
     def take_action(self, parsed_args):
         client = self.get_client()
+        if not parsed_args.tag:
+            raise exceptions.CommandError(
+                _('Cannot add an empty value as tag'))
         resource_type, resource_id = _convert_resource_args(client,
                                                             parsed_args)
         client.add_tag(resource_type, resource_id, parsed_args.tag)
diff --git a/neutronclient/tests/unit/test_cli20_tag.py b/neutronclient/tests/unit/test_cli20_tag.py
index edd70a7..1b04be6 100644
--- a/neutronclient/tests/unit/test_cli20_tag.py
+++ b/neutronclient/tests/unit/test_cli20_tag.py
@@ -81,6 +81,14 @@ class CLITestV20Tag(test_cli20.CLITestV20Base):
                 '--tag', 'red']
         self._test_tag_operation(cmd, path, 'PUT', args, "tag-add")
 
+    def test_add_tag_empty_tag(self):
+        cmd = tag.AddTag(test_cli20.MyApp(sys.stdout), None)
+        path = self._make_tag_path('network', 'myid', '')
+        args = ['--resource-type', 'network', '--resource', 'myid',
+                '--tag', '']
+        self.assertRaises(exceptions.CommandError, self._test_tag_operation,
+                          cmd, path, 'PUT', args, "tag-add")
+
     def test_replace_tag(self):
         cmd = tag.ReplaceTag(test_cli20.MyApp(sys.stdout), None)
         path = self._make_tags_path('network', 'myid')