fix versionadded to 3.4
diff --git a/Doc/library/filecmp.rst b/Doc/library/filecmp.rst
index 8577c17..e5ffefb 100644
--- a/Doc/library/filecmp.rst
+++ b/Doc/library/filecmp.rst
@@ -166,7 +166,7 @@
 
 .. attribute:: DEFAULT_IGNORES
 
-   .. versionadded:: 3.3
+   .. versionadded:: 3.4
 
    List of directories ignored by :class:`dircmp` by default.