#7417: add signature to open() docstring.
diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c
index 14a4356..e20a2f6 100644
--- a/Modules/_io/_iomodule.c
+++ b/Modules/_io/_iomodule.c
@@ -176,6 +176,9 @@
* The main open() function
*/
PyDoc_STRVAR(open_doc,
+"open(file, mode='r', buffering=None, encoding=None,\n"
+" errors=None, newline=None, closefd=True) -> file object\n"
+"\n"
"Open file and return a stream. Raise IOError upon failure.\n"
"\n"
"file is either a text or byte string giving the name (and the path\n"