diff --git a/pkgs/by-name/wa/waffle/package.nix b/pkgs/by-name/wa/waffle/package.nix
index 477b92ec59bb..0fb776f8cb27 100644
--- a/pkgs/by-name/wa/waffle/package.nix
+++ b/pkgs/by-name/wa/waffle/package.nix
@@ -71,7 +71,7 @@ stdenv.mkDerivation rec {
     wayland-scanner
   ];
 
-  PKG_CONFIG_BASH_COMPLETION_COMPLETIONSDIR = "${placeholder "out"}/share/bash-completion/completions";
+  env.PKG_CONFIG_BASH_COMPLETION_COMPLETIONSDIR = "${placeholder "out"}/share/bash-completion/completions";
 
   postInstall = ''
     wrapProgram $out/bin/wflinfo \