diff --git a/lib/lists.nix b/lib/lists.nix
new file mode 100644
index 0000000..a3720bf
--- /dev/null
+++ b/lib/lists.nix
@@ -0,0 +1,13 @@
+{ lib, ... }:
+let
+  inherit (lib) filter;
+in
+{
+  # Filter a list using a predicate function after applying a map.
+  #
+  # mapFilter ::
+  #   (value -> bool)
+  #   (any -> value)
+  #   [ any ]
+  mapFilter = pred: f: attrs: filter pred (map f attrs);
+}