diff --git a/docs/source/reference/functions.rst b/docs/source/reference/functions.rst
index 08650e866fe9..ba8fe8ab86e9 100644
--- a/docs/source/reference/functions.rst
+++ b/docs/source/reference/functions.rst
@@ -70,6 +70,7 @@ Array manipulations
    chainer.functions.hstack
    chainer.functions.im2col
    chainer.functions.pad
+   chainer.functions.pad_sequence
    chainer.functions.permutate
    chainer.functions.reshape
    chainer.functions.resize_images