diff --git a/doc/manual/installing.rst b/doc/manual/installing.rst
index 24cfabd98..c18f935e5 100644
--- a/doc/manual/installing.rst
+++ b/doc/manual/installing.rst
@@ -23,10 +23,10 @@ Once Nix is installed, add the M-Labs package channel with: ::
 
   $ nix-channel --add https://nixbld.m-labs.hk/channel/custom/artiq/full-legacy/artiq-full
 
-Those channels track `nixpkgs 20.09 <https://github.com/NixOS/nixpkgs/tree/release-20.09>`_. You can check the latest status through the `Hydra interface <https://nixbld.m-labs.hk>`_. As the Nix package manager default installation uses the development version of nixpkgs, we need to tell it to switch to the release: ::
+Those channels track `nixpkgs 21.05 <https://github.com/NixOS/nixpkgs/tree/release-21.05>`_. You can check the latest status through the `Hydra interface <https://nixbld.m-labs.hk>`_. As the Nix package manager default installation uses the development version of nixpkgs, we need to tell it to switch to the release: ::
 
   $ nix-channel --remove nixpkgs
-  $ nix-channel --add https://nixos.org/channels/nixos-20.09 nixpkgs
+  $ nix-channel --add https://nixos.org/channels/nixos-21.05 nixpkgs
 
 Finally, make all the channel changes effective: ::