diff --git a/README.md b/README.md
index 49fd954..00a6945 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@
 Our build environment is self-contained and requires only minimal host dependencies:
 
 - A Linux machine or VM.
-- [Bazelisk](https://github.com/bazelbuild/bazelisk) >= v1.15.0
+- [Bazelisk](https://github.com/bazelbuild/bazelisk) >= v1.15.0 (or a working Nix environment).
 - A reasonably recent kernel with user namespaces enabled.
 - Working KVM with access to `/dev/kvm` (if you want to run tests).
 
diff --git a/SETUP.md b/SETUP.md
index d48e894..695dd47 100644
--- a/SETUP.md
+++ b/SETUP.md
@@ -76,11 +76,10 @@
 
 ### NixOS
 
-We fully support building on NixOS, and we provide a `shell.nix` file to make it easy:
+We fully support building on NixOS, and we provide a `shell.nix` file to make it easy. Just run `nix-shell` in the
+project root! This will drop you into a shell with all dependencies installed, and you can run `bazel ...` as usual.
 
-    nix-shell --pure
-
-(just don't look at it too closely unless you want toolchain-themed nightmares)
+If you're using IntelliJ, you have to run IntelliJ _inside_ the Nix shell.
 
 ## IntelliJ