diff --git a/pkgs/development/python-modules/binaryornot/default.nix b/pkgs/development/python-modules/binaryornot/default.nix
index 2f0b01a5c23..77f1ff7cbd0 100644
--- a/pkgs/development/python-modules/binaryornot/default.nix
+++ b/pkgs/development/python-modules/binaryornot/default.nix
@@ -10,9 +10,9 @@ buildPythonPackage rec {
   };
 
   prePatch = ''
-    # See https://github.com/audreyr/binaryornot/issues/40
+    # TypeError: binary() got an unexpected keyword argument 'average_size'
     substituteInPlace tests/test_check.py \
-      --replace "average_size=512" "average_size=128"
+      --replace "average_size=512" ""
   '';
 
   propagatedBuildInputs = [ chardet ];