diff --git a/horizon/test/tests/templatetags.py b/horizon/test/tests/templatetags.py
index e9c3f6791f..899d987144 100644
--- a/horizon/test/tests/templatetags.py
+++ b/horizon/test/tests/templatetags.py
@@ -43,8 +43,9 @@ class TemplateTagTests(test.TestCase):
         tag_call = "{%% %s %%}" % tag_name
         return self.render_template(tag_call, tag_require)
 
-    def render_template(self, template_text, tag_require='', context={}):
+    def render_template(self, template_text, tag_require='', context=None):
         """Render a Custom Template to string."""
+        context = context or {}
         template = Template("{%% load %s %%} %s"
                             % (tag_require, template_text))
         return template.render(Context(context))
diff --git a/openstack_dashboard/api/glance.py b/openstack_dashboard/api/glance.py
index 35ab7ab70c..7f21b31615 100644
--- a/openstack_dashboard/api/glance.py
+++ b/openstack_dashboard/api/glance.py
@@ -316,8 +316,9 @@ def metadefs_namespace_list(request,
     return namespaces, has_more_data, has_prev_data
 
 
-def metadefs_namespace_full_list(request, resource_type, filters={},
+def metadefs_namespace_full_list(request, resource_type, filters=None,
                                  *args, **kwargs):
+    filters = filters or {}
     filters['resource_types'] = [resource_type]
     namespaces, has_more_data, has_prev_data = metadefs_namespace_list(
         request, filters, *args, **kwargs
diff --git a/openstack_dashboard/api/rest/utils.py b/openstack_dashboard/api/rest/utils.py
index b7d3dcdfbc..afe6e0b725 100644
--- a/openstack_dashboard/api/rest/utils.py
+++ b/openstack_dashboard/api/rest/utils.py
@@ -147,7 +147,7 @@ def ajax(authenticated=True, data_required=False,
     return decorator
 
 
-def parse_filters_kwargs(request, client_keywords={}):
+def parse_filters_kwargs(request, client_keywords=None):
     """Extract REST filter parameters from the request GET args.
 
     Client processes some keywords separately from filters and takes
@@ -156,6 +156,7 @@ def parse_filters_kwargs(request, client_keywords={}):
     """
     filters = {}
     kwargs = {}
+    client_keywords = client_keywords or {}
     for param in request.GET:
         if param in client_keywords:
             kwargs[param] = request.GET[param]