diff --git a/README.md b/README.md
index 5687a2a..8d2c71b 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@ It is built around the [httpsig](https://github.com/common-fate/httpsig) library
 
 # Try it out
 
-If you use Nix shell, there is a `shell.nix` config in the repo that should give you a working environment for running the project. If you can't/don't want to use Nix then the only requirements are Go and Caddy. (And possibly gcc. Is it safe to assume you'll have that?)
+If you use Nix shell, there is a `shell.nix` config in the repo that should give you a working environment for running the project. If you can't/don't want to use Nix then the only requirements are Go and Caddy. (And possibly gcc, for the sqlite library. I have not tested this project on a system without gcc.)
 
 One program runs both the server and a test client.