document new fix_callable behavior

diff --git a/Doc/library/2to3.rst b/Doc/library/2to3.rst
index d9eb00c277f684ba886ed59f3e2702038d5e6d87..20a6245dc656d989e1d38ab1c115cb7630e22e7a 100644 (file)
--- a/Doc/library/2to3.rst
+++ b/Doc/library/2to3.rst
@@ -122,7 +122,8 @@ and off individually.  They are described here in more detail.
 
 .. 2to3fixer:: callable
 
-   Converts ``callable(x)`` to ``hasattr(x, "__call_")``.
+   Converts ``callable(x)`` to ``isinstance(x, collections.Callable)``, adding
+   an import to :mod:`collections` if needed.
 
 .. 2to3fixer:: dict