diff --git a/Lib/argparse.py b/Lib/argparse.py
index b2db312..e177e4f 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1672,7 +1672,8 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
     """Object for parsing command line strings into Python objects.
 
     Keyword Arguments:
-        - prog -- The name of the program (default: sys.argv[0])
+        - prog -- The name of the program (default:
+            ``os.path.basename(sys.argv[0])``)
         - usage -- A usage message (default: auto-generated from arguments)
         - description -- A description of what the program does
         - epilog -- Text following the argument descriptions