These are the commands I used to setup NixOS-WSL as my default shell on my Windows 11 gaming machine running OpenSSH. This article assumes that your default WSL distribution is NixOS-WSL.

Setup /bin/bash symlink #

In order to use WSL as the default shell for OpenSSH on Windows, you need to use C:\Windows\System32\bash.exe – not C:\Windows\System32\wsl.exe. This command assumes that /bin/bash exists in your WSL distribution and by default on NixOS-WSL, it does not.

Add the following to /etc/nixos/configuration.nix to create a symlink to bash for bash.exe to use:

wsl.extraBin = [{
  name = "bash";
  src = "${pkgs.bash}/bin/bash";
}];

Set WSL as the default shell for SSH #

Run the following command in an Administrator PowerShell session to set WSL as your default shell for Windows:

New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShell -Value "C:\Windows\System32\bash.exe" -PropertyType String -Force

BONUS: SSH key auth for admin users #

In an Administrator PowerShell session, place your authorized_keys file at the following path:

C:\ProgramData\ssh\administrators_authorized_keys

I used to the following one-liner in an Administrator PowerShell session to setup my permitted SSH keys from GitHub:

curl.exe -L https://github.com/heywoodlh.keys -o "C:\ProgramData\ssh\administrators_authorized_keys"

Restart SSH #

Run the following command in Administrator PowerShell session to restart SSH:

Restart-Service sshd