diff --git a/pkgs/by-name/es/espeakup/package.nix b/pkgs/by-name/es/espeakup/package.nix
index 7701a3475ee1..3fe87c511371 100644
--- a/pkgs/by-name/es/espeakup/package.nix
+++ b/pkgs/by-name/es/espeakup/package.nix
@@ -35,7 +35,7 @@ stdenv.mkDerivation rec {
     systemd
   ];
 
-  PKG_CONFIG_SYSTEMD_SYSTEMDSYSTEMUNITDIR = "${placeholder "out"}/lib/systemd/system";
+  env.PKG_CONFIG_SYSTEMD_SYSTEMDSYSTEMUNITDIR = "${placeholder "out"}/lib/systemd/system";
 
   meta = {
     homepage = "https://github.com/linux-speakup/espeakup";