diff --git a/build.sh b/build.sh
index 51e68ba..e498b8b 100755
--- a/build.sh
+++ b/build.sh
@@ -14,17 +14,6 @@ set -Eexuo pipefail
 
 # NOTE: If vars not imported - set to the default value
 compiler=${compiler:-'ghc8101'}
-# NOTE: Nix by default uses nixpkgs-unstable channel
-# Setup for Nixpkgs revision:
-#   `rev` vals in order of freshness -> cache & stability:
-#   { master
-#   , commitHash
-#   , haskell-updates  # Haskell development branch in Nixpkgs, can be inconsistent. Weekly merged into the upstream
-#   , nixpkgs-unstable  # Default branch on Nix installation, default for non NixOS
-#   , nixos-unstable  # nixpkgs-unstable that passes a bunch of base tests
-#   , nixos-20.03  # Last stable release, gets almost no updates to recipes, gets only required backports
-#   ...
-#   }
 rev=${rev:-'nixpkgs-unstable'}
 # If NIX_PATH not imported - construct it from `rev`
 NIX_PATH=${NIX_PATH:-"nixpkgs=https://github.com/nixos/nixpkgs/archive/$rev.tar.gz"}
diff --git a/default.nix b/default.nix
index ff905bf..73acc96 100644
--- a/default.nix
+++ b/default.nix
@@ -68,7 +68,17 @@
 
 
 , useRev ? false
-# Accepts Nixpkgs channel name and Git revision
+# Nix by default uses nixpkgs-unstable channel
+# Nixpkgs revision options:
+#   `rev` vals in order of freshness -> cache & stability:
+#   { master
+#   , <commitHash>
+#   , haskell-updates  # Haskell development branch in Nixpkgs, can be inconsistent. Weekly merged into the upstream
+#   , nixpkgs-unstable  # Default branch on Nix installation, default for non NixOS
+#   , nixos-unstable  # nixpkgs-unstable that passes a bunch of base tests
+#   , nixos-20.03  # Last stable release, gets almost no updates to recipes, gets only required backports
+#   ...
+#   }
 , rev ? "nixpkgs-unstable"
 
 , pkgs ?