diff --git a/docs/source/reference/functions.rst b/docs/source/reference/functions.rst
index 357d81e9bfc5..69ddef80fe9a 100644
--- a/docs/source/reference/functions.rst
+++ b/docs/source/reference/functions.rst
@@ -69,6 +69,7 @@ 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