diff --git a/doc/filters/length.rst b/doc/filters/length.rst
index 8b504ed25..37209f8f4 100644
--- a/doc/filters/length.rst
+++ b/doc/filters/length.rst
@@ -14,7 +14,7 @@ return value of the ``count()`` method.
 For objects that implement the ``__toString()`` magic method (and not ``Countable``),
 it will return the length of the string provided by that method.
 
-For objects that implement the ``IteratorAggregate`` interface, ``length`` will use the return value of the ``iterator_count()`` method.
+For objects that implement the ``Traversable`` interface, ``length`` will use the return value of the ``iterator_count()`` method.
 
 .. code-block:: twig