diff --git a/pkgs/tools/X11/xmacro/default.nix b/pkgs/tools/X11/xmacro/default.nix
index e986b46aa487..fee601d15750 100644
--- a/pkgs/tools/X11/xmacro/default.nix
+++ b/pkgs/tools/X11/xmacro/default.nix
@@ -15,5 +15,6 @@ stdenv.mkDerivation rec {
 
   meta = {
     platforms = stdenv.lib.platforms.linux;
+    license = stdenv.lib.licenses.gpl2;
   };
 }