diff --git a/Misc/ACKS b/Misc/ACKS
index a46ee84..f534143 100644
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -305,6 +305,7 @@
 Frederik Fix
 Matt Fleming
 Hernán Martínez Foffani
+Arnaud Fontaine
 Michael Foord
 Amaury Forgeot d'Arc
 Doug Fort
diff --git a/Misc/NEWS b/Misc/NEWS
index 8b0b145..c78dc96 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -112,6 +112,12 @@
 Library
 -------
 
+- Issue #12776,#11839: call argparse type function (specified by add_argument)
+  only once. Before, the type function was called twice in the case where the
+  default was specified and the argument was given as well.  This was
+  especially problematic for the FileType type, as a default file would always
+  be opened, even if a file argument was specified on the command line.
+
 - Issue #13370: Ensure that ctypes works on Mac OS X when Python is
   compiled using the clang compiler