diff --git a/pkgs/development/ocaml-modules/asetmap/default.nix b/pkgs/development/ocaml-modules/asetmap/default.nix
index 0c1037e1c5ff..840cf7a5ae3a 100644
--- a/pkgs/development/ocaml-modules/asetmap/default.nix
+++ b/pkgs/development/ocaml-modules/asetmap/default.nix
@@ -1,4 +1,5 @@
 {
+  lib,
   fetchurl,
   buildDunePackage,
   topkg,
@@ -27,5 +28,8 @@ buildDunePackage (finalAttrs: {
 
   inherit (topkg) buildPhase installPhase;
 
-  meta = { inherit (ocaml.meta) platforms; };
+  meta = {
+    inherit (ocaml.meta) platforms;
+    license = lib.licenses.isc;
+  };
 })