diff --git a/pkgs/build-support/build-fhs-chrootenv/default.nix b/pkgs/build-support/build-fhs-chrootenv/default.nix
index b325c22a25a1..89dd2faf3ba4 100644
--- a/pkgs/build-support/build-fhs-chrootenv/default.nix
+++ b/pkgs/build-support/build-fhs-chrootenv/default.nix
@@ -213,7 +213,7 @@ in stdenv.mkDerivation {
     cd "$out/sw"
     ${extraBuildCommands}
     cd "$out/sw"
-    ${extraBuildCommandsMulti}
+    ${if isMultiBuild then extraBuildCommandsMulti else ""}
     cd ..
   '';
 }