diff --git a/pkgs/build-support/docker/stream_layered_image.py b/pkgs/build-support/docker/stream_layered_image.py
index 8ffd336fce49..ffb6ba0ade4b 100644
--- a/pkgs/build-support/docker/stream_layered_image.py
+++ b/pkgs/build-support/docker/stream_layered_image.py
@@ -74,6 +74,10 @@ def archive_paths_to(obj, paths, mtime, add_nix, filter=None):
         ti.gname = "root"
         return filter(ti)
 
+    def nix_root(ti):
+        ti.mode = 0o0555  # r-xr-xr-x
+        return ti
+
     def dir(path):
         ti = tarfile.TarInfo(path)
         ti.type = tarfile.DIRTYPE
@@ -84,8 +88,8 @@ def archive_paths_to(obj, paths, mtime, add_nix, filter=None):
         # these directories first when building layer tarballs. But
         # we don't need them on the customisation layer.
         if add_nix:
-            tar.addfile(apply_filters(dir("/nix")))
-            tar.addfile(apply_filters(dir("/nix/store")))
+            tar.addfile(apply_filters(nix_root(dir("/nix"))))
+            tar.addfile(apply_filters(nix_root(dir("/nix/store"))))
 
         for path in paths:
             path = pathlib.Path(path)