diff --git a/package.yaml b/package.yaml
index 1baa194..c1e5aad 100644
--- a/package.yaml
+++ b/package.yaml
@@ -1,6 +1,7 @@
 # Adapted from new-template.hsfiles
 
 name:                utoy
+# Keep this in sync with the version in flake.nix.
 version:             0.5
 git:                 "https://git.pbrinkmeier.de/paul/utoy"
 license:             MIT
diff --git a/stack.yaml b/stack.yaml
index 8f828e5..737c32b 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -1,4 +1,5 @@
 # You can get a working environment using nix develop.
+# Keep this in sync with nix/settings.nix
 resolver: ghc-9.4.4
 packages:
 - .