diff --git a/pkgs/by-name/ls/lsof/package.nix b/pkgs/by-name/ls/lsof/package.nix
index f438a33b5465..8976e83d5069 100644
--- a/pkgs/by-name/ls/lsof/package.nix
+++ b/pkgs/by-name/ls/lsof/package.nix
@@ -49,7 +49,7 @@ stdenv.mkDerivation rec {
   buildInputs = [ ncurses ];
 
   # Stop build scripts from searching global include paths
-  LSOF_INCLUDE = "${lib.getDev stdenv.cc.libc}/include";
+  env.LSOF_INCLUDE = "${lib.getDev stdenv.cc.libc}/include";
   configurePhase =
     let
       genericFlags = "LSOF_CC=$CC LSOF_AR=\"$AR cr\" LSOF_RANLIB=$RANLIB";