Grammar fix
diff --git a/Doc/library/email.message.rst b/Doc/library/email.message.rst
index e1fb20e..850072b 100644
--- a/Doc/library/email.message.rst
+++ b/Doc/library/email.message.rst
@@ -38,7 +38,7 @@
 
 .. method:: Message.as_string([unixfrom])
 
-   Return the entire message flatten as a string.  When optional *unixfrom* is
+   Return the entire message flattened as a string.  When optional *unixfrom* is
    ``True``, the envelope header is included in the returned string.  *unixfrom*
    defaults to ``False``.