diff --git a/Lib/io.py b/Lib/io.py
index 87fab92..6c7cec9 100644
--- a/Lib/io.py
+++ b/Lib/io.py
@@ -67,6 +67,9 @@
 
 OpenWrapper = _io.open # for compatibility with _pyio
 
+# Pretend this exception was created here.
+UnsupportedOperation.__module__ = "io"
+
 # for seek()
 SEEK_SET = 0
 SEEK_CUR = 1