diff --git a/pkgs/build-support/vm/default.nix b/pkgs/build-support/vm/default.nix
index 6af4a5c0574..777cc72aa0b 100644
--- a/pkgs/build-support/vm/default.nix
+++ b/pkgs/build-support/vm/default.nix
@@ -250,6 +250,7 @@ rec {
         path = $TMPDIR/xchg
         read only = no
         guest ok = yes
+      $EXTRA_SAMBA_CONF
       SMB
 
       rm -f ./samba