diff --git a/corehq/ex-submodules/casexml/apps/case/tests/test_multimedia.py b/corehq/ex-submodules/casexml/apps/case/tests/test_multimedia.py
index b424cb603d52..6dc5a15375b8 100644
--- a/corehq/ex-submodules/casexml/apps/case/tests/test_multimedia.py
+++ b/corehq/ex-submodules/casexml/apps/case/tests/test_multimedia.py
@@ -358,5 +358,10 @@ def __init__(self, fileobj):
     def __getattr__(self, name):
         return getattr(self.fileobj, name)
 
+    def open(self, *args, **kw):
+        # compatible with django.core.files.base.File.open()
+        obj = self.fileobj.open(*args, **kw)
+        return self if obj is self.fileobj else obj
+
     def close(self):
         pass
diff --git a/corehq/form_processor/models.py b/corehq/form_processor/models.py
index 5d3da1324dd9..d94fea7f2f09 100644
--- a/corehq/form_processor/models.py
+++ b/corehq/form_processor/models.py
@@ -151,6 +151,7 @@ def open(self):
             return BytesIO(self.content)
         fileobj = self.raw_content.open()
 
+        # TODO remove when Django 1 is no longer supported
         if fileobj is None:
             assert not isinstance(self.raw_content, BlobMeta), repr(self)
             # work around Django 1.11 bug, fixed in 2.0