diff --git a/pkgs/by-name/pp/ppp/package.nix b/pkgs/by-name/pp/ppp/package.nix
index a4c577d4c015..547c7ee8f7dd 100644
--- a/pkgs/by-name/pp/ppp/package.nix
+++ b/pkgs/by-name/pp/ppp/package.nix
@@ -73,7 +73,7 @@ stdenv.mkDerivation (finalAttrs: {
     "CC=${stdenv.cc.targetPrefix}cc"
   ];
 
-  NIX_LDFLAGS = "-lcrypt";
+  env.NIX_LDFLAGS = "-lcrypt";
 
   installFlags = [
     "sysconfdir=$(out)/etc"