diff --git a/morph/grid/local/README.rst b/morph/grid/local/README.rst
index 0920afa4d31e91bcd0450493093131979234b1ba..e11d92a1fd9660cc850d5ff939d252c500c7d912 100644
--- a/morph/grid/local/README.rst
+++ b/morph/grid/local/README.rst
@@ -78,7 +78,24 @@ Build and start the VMs::
 
   VAGRANT_DEFAULT_PROVIDER=virtualbox vagrant up
 
-Then::
+Then, once::
+
+  vagrant ssh-config > ./vagrant-ssh-config
+
+Add the IPs from ``grid.nix`` to the vagrant-ssh-config Host match blocks so the config reads like::
+
+  Host payments1 192.168.67.21
+    HostName 192.168.67.21
+    User vagrant
+    [...]
+
+Then, make morph use this ssh config either - with newer morph - point it to it::
+
+  export SSH_CONFIG_FILE=./vagrant-ssh-config
+
+Or, with older morph, adding the config to your user's ``~/.ssh/config`` file.
+
+Then, build and deploy our software to the Vagrant VMs::
 
   morph build grid.nix
   morph push grid.nix
diff --git a/morph/grid/local/Vagrantfile b/morph/grid/local/Vagrantfile
index 7c20fddda1516d31abd65c9850abaf7619ce8030..81dec21ee701d761b4347f11df43398d78d4b528 100644
--- a/morph/grid/local/Vagrantfile
+++ b/morph/grid/local/Vagrantfile
@@ -33,6 +33,7 @@ Vagrant.configure("2") do |config|
   end
 
   # To make the VMs assign the static IPs to the network interfaces we need a rebuild:
+  config.vm.provision "shell", inline: "echo '{nix.trustedUsers = [ \"@wheel\" \"root\" \"vagrant\" ];}' > /etc/nixos/custom-configuration.nix"
   config.vm.provision "shell", inline: "nixos-rebuild switch"
 
   config.trigger.after :up do |trigger|