diff --git a/doc/api.rst b/doc/api.rst
index d2309f28226..94407f2783f 100644
--- a/doc/api.rst
+++ b/doc/api.rst
@@ -410,7 +410,7 @@ Universal functions
    for the ``xarray.ufuncs`` module, which should not be used for new code
    unless compatibility with versions of NumPy prior to v1.13 is required.
 
-This functions are copied from NumPy, but extended to work on NumPy arrays,
+These functions are copied from NumPy, but extended to work on NumPy arrays,
 dask arrays and all xarray objects. You can find them in the ``xarray.ufuncs``
 module: