diff --git a/day1/default.nix b/day1/default.nix
index f87383e..6e69d0f 100644
--- a/day1/default.nix
+++ b/day1/default.nix
@@ -4,9 +4,9 @@ with builtins;
 with utils;
 let
   numbers = map (l: map toInt (splitWhitespace l)) (readLines ./input);
-  left = sortOn noop (map (flip elemAt 0) numbers);
-  right = sortOn noop (map (flip elemAt 1) numbers);
+  left = sort lessThan (map (flip elemAt 0) numbers);
+  right = sort lessThan (map (flip elemAt 1) numbers);
 in {
   part1 = listSum (zipListsWith delta left right);
-  part2 = listSum (map (x: x * (count (y: x == y) right)) left);
+  part2 = listSum (map (x: x * (count (eq x) right)) left);
 }
diff --git a/utils.nix b/utils.nix
index 0dae919..bcc7e79 100644
--- a/utils.nix
+++ b/utils.nix
@@ -5,6 +5,6 @@ with builtins; rec {
   splitWhitespace = s: filter isString (builtins.split "[[:space:]]+" s);
   abs = i: if i >= 0 then i else i * -1;
   delta = x: y: abs (x - y);
-  noop = x: x;
   listSum = foldl' add 0;
+  eq = x: y: x == y;
 }