diff --git a/utils/nixFilesIn.nix b/utils/nixFilesIn.nix
new file mode 100644
index 0000000..c3ff263
--- /dev/null
+++ b/utils/nixFilesIn.nix
@@ -0,0 +1,4 @@
+lib: dir:
+map (name: dir + "/${name}") (lib.attrNames
+  (lib.filterAttrs (name: type: type == "regular" && lib.hasSuffix ".nix" name)
+    (builtins.readDir dir)))