diff --git a/pkgs/build-support/trivial-builders.nix b/pkgs/build-support/trivial-builders.nix
index 5ae2e7b4fc9b..c08a6c3a265f 100644
--- a/pkgs/build-support/trivial-builders.nix
+++ b/pkgs/build-support/trivial-builders.nix
@@ -33,6 +33,7 @@ rec {
     
   # Shorthands for `writeTextFile'.
   writeText = name: text: writeTextFile {inherit name text;};
+  writeTextDir = name: text: writeTextFile {inherit name text; destination = "/${name}";};
   writeScript = name: text: writeTextFile {inherit name text; executable = true;};
   writeScriptBin = name: text: writeTextFile {inherit name text; executable = true; destination = "/bin/${name}";};