diff --git a/Doc/library/email.generator.rst b/Doc/library/email.generator.rst
index 002f36f..2c169b9 100644
--- a/Doc/library/email.generator.rst
+++ b/Doc/library/email.generator.rst
@@ -95,7 +95,7 @@
 formatted string representation of a message object.  For more detail, see
 :mod:`email.message`.
 
-.. class:: BytesGenerator(outfp, mangle_from_=True, maxheaderlen=78, fmt=None)
+.. class:: BytesGenerator(outfp, mangle_from_=True, maxheaderlen=78)
 
    This class has the same API as the :class:`Generator` class, except that
    *outfp* must be a file like object that will accept :class`bytes` input to