casa-mp-base

diff --git test/mitmproxy/addons/test_readfile.py test/mitmproxy/addons/test_readfile.py

index 3d28d8b7d..94e18cdb3 100644

--- test/mitmproxy/addons/test_readfile.py

+++ test/mitmproxy/addons/test_readfile.py

@@ -30,8 +30,8 @@ def data():

 @pytest.fixture

-def corrupt_data():

-    f = data()

+def corrupt_data(data):

+    f = io.BytesIO(data.getvalue())

     f.seek(0, io.SEEK_END)

     f.write(b"qibble")

     f.seek(0)