diff --git a/pkgs/by-name/x1/x11spice/package.nix b/pkgs/by-name/x1/x11spice/package.nix
index 1e3d42e4dc31..df02a65b80a7 100644
--- a/pkgs/by-name/x1/x11spice/package.nix
+++ b/pkgs/by-name/x1/x11spice/package.nix
@@ -38,7 +38,7 @@ stdenv.mkDerivation {
     spice-protocol
   ];
 
-  NIX_LDFLAGS = "-lpthread";
+  env.NIX_LDFLAGS = "-lpthread";
 
   meta = {
     description = "Enable a running X11 desktop to be available via a Spice server";