diff --git a/pkgs/build-support/build-fhs-chrootenv/default.nix b/pkgs/build-support/build-fhs-chrootenv/default.nix
index 8f24ab5e63c..461f4762aba 100644
--- a/pkgs/build-support/build-fhs-chrootenv/default.nix
+++ b/pkgs/build-support/build-fhs-chrootenv/default.nix
@@ -11,7 +11,8 @@ let
   name = env.pname;
 
 in stdenv.mkDerivation {
-  name         = "${name}-chrootenv";
+  name = "${name}-chrootenv";
+  preferLocalBuild = true;
   buildCommand = ''
     mkdir -p $out/bin
     cd $out/bin
diff --git a/pkgs/build-support/build-fhs-chrootenv/env.nix b/pkgs/build-support/build-fhs-chrootenv/env.nix
index 12c0fff7510..b810adefab1 100644
--- a/pkgs/build-support/build-fhs-chrootenv/env.nix
+++ b/pkgs/build-support/build-fhs-chrootenv/env.nix
@@ -170,6 +170,7 @@ in nixpkgs.stdenv.mkDerivation {
     cd $out
     ${if isMultiBuild then extraBuildCommandsMulti else ""}
   '';
+  preferLocalBuild = true;
   passthru = {
     pname = name;
   };
diff --git a/pkgs/build-support/build-fhs-userenv/default.nix b/pkgs/build-support/build-fhs-userenv/default.nix
index b3bbc19dda8..57864b4934b 100644
--- a/pkgs/build-support/build-fhs-userenv/default.nix
+++ b/pkgs/build-support/build-fhs-userenv/default.nix
@@ -15,8 +15,9 @@ let
   };
 
 in stdenv.mkDerivation {
-  name         = "${name}-userenv";
+  name = "${name}-userenv";
   buildInputs = [ ruby ];
+  preferLocalBuild = true;
   buildCommand = ''
     mkdir -p $out/bin
     cat > $out/bin/${name} <<EOF