diff --git a/rest_framework/mixins.py b/rest_framework/mixins.py
index 1edcfa5c9..27adeabbf 100644
--- a/rest_framework/mixins.py
+++ b/rest_framework/mixins.py
@@ -14,8 +14,10 @@ class CreateModelMixin(object):
     Create a model instance.
     Should be mixed in with any `BaseView`.
     """
-    def create(self, request, *args, **kwargs):
-        serializer = self.get_serializer(data=request.DATA, files=request.FILES)
+    def create(self, request, data=None, *args, **kwargs):
+        if data is None:
+            data = request.DATA
+        serializer = self.get_serializer(data=data, files=request.FILES)
         if serializer.is_valid():
             self.pre_save(serializer.object)
             self.object = serializer.save()
@@ -81,7 +83,7 @@ class UpdateModelMixin(object):
     Update a model instance.
     Should be mixed in with `SingleObjectBaseView`.
     """
-    def update(self, request, *args, **kwargs):
+    def update(self, request, data=None, *args, **kwargs):
         try:
             self.object = self.get_object()
             created = False
@@ -89,7 +91,10 @@ class UpdateModelMixin(object):
             self.object = None
             created = True
 
-        serializer = self.get_serializer(self.object, data=request.DATA, files=request.FILES)
+        if data is None:
+            data = request.DATA
+
+        serializer = self.get_serializer(self.object, data=data, files=request.FILES)
 
         if serializer.is_valid():
             self.pre_save(serializer.object)