diff --git a/pkgs/build-support/trivial-builders.nix b/pkgs/build-support/trivial-builders.nix
index d6f390ddfb1c..1529869aa331 100644
--- a/pkgs/build-support/trivial-builders.nix
+++ b/pkgs/build-support/trivial-builders.nix
@@ -108,8 +108,9 @@ rec {
 
   # Quickly create a set of symlinks to derivations.
   # entries is a list of attribute sets like { name = "name" ; path = "/nix/store/..."; }
-  linkFarm = name: entries: runCommand name {} ("mkdir -p $out; cd $out; \n" +
-    (lib.concatMapStrings (x: "ln -s '${x.path}' '${x.name}';\n") entries));
+  linkFarm = name: entries: runCommand name { preferLocalBuild = true; }
+    ("mkdir -p $out; cd $out; \n" +
+      (lib.concatMapStrings (x: "ln -s '${x.path}' '${x.name}';\n") entries));
 
 
   # Print an error message if the file with the specified name and