diff --git a/pkgs/build-support/src-only/default.nix b/pkgs/build-support/src-only/default.nix
index cd8572629cad..2b0db0e267aa 100644
--- a/pkgs/build-support/src-only/default.nix
+++ b/pkgs/build-support/src-only/default.nix
@@ -13,7 +13,7 @@ let
 in
 stdenv.mkDerivation (args // {
   name = "${name}-source";
-  installPhase = "cp -pr --reflink=auto -- . $out";
+  installPhase = "cp -r . $out";
   outputs = [ "out" ];
   separateDebugInfo = false;
   dontUnpack = false;