diff --git a/modules/swagger-codegen/src/main/resources/python/api_client.mustache b/modules/swagger-codegen/src/main/resources/python/api_client.mustache
index e75c6be52ed..2ea9b2299cc 100644
--- a/modules/swagger-codegen/src/main/resources/python/api_client.mustache
+++ b/modules/swagger-codegen/src/main/resources/python/api_client.mustache
@@ -581,6 +581,9 @@ class ApiClient(object):
         """
         instance = klass()
 
+        if(not instance.swagger_types):
+            return data
+
         for attr, attr_type in iteritems(instance.swagger_types):
             if data is not None \
                and instance.attribute_map[attr] in data\