diff --git a/pkgs/development/ocaml-modules/ocsigen-server/default.nix b/pkgs/development/ocaml-modules/ocsigen-server/default.nix
index 6f68958aeab..e33d4037379 100644
--- a/pkgs/development/ocaml-modules/ocsigen-server/default.nix
+++ b/pkgs/development/ocaml-modules/ocsigen-server/default.nix
@@ -29,7 +29,7 @@ stdenv.mkDerivation {
     longDescription =''
       A full featured Web server. It implements most features of the HTTP protocol, and has a very powerful extension mechanism that make very easy to plug your own OCaml modules for generating pages.
       '';
-    license = "LGPL"; # <- todo: check
+    license = stdenv.lib.licenses.lgpl21;
     platforms = ocaml.meta.platforms;
     maintainers = [ stdenv.lib.maintainers.gal_bolle ];
   };