diff --git a/README.md b/README.md
index 8a78a9d..7a60689 100644
--- a/README.md
+++ b/README.md
@@ -166,6 +166,15 @@ $ nix eval .#nixosConfigurations.nuc.config.networking.firewall.allowedTCPPorts
 9093 9100 9883 ]
 ```
 
+Push a [runtime closure](https://docs.cachix.org/pushing#pushing-runtime-closure) of a locally built derivation to Cachix:
+
+```
+export CACHIX_AUTH_TOKEN=...
+nix build -L --json  .#nixosConfigurations.rp3.config.system.build.toplevel \
+    | nix run nixpkgs#jq -- -r '.[].outputs | to_entries[].value'
+    | nix run nixpkgs#cachix -- push wagdav
+```
+
 ## Router
 
 Linksys WRT ACM-3200 running OpenWRT.