diff --git a/pkgs/by-name/du/duckmarines/package.nix b/pkgs/by-name/du/duckmarines/package.nix
index d3bda6ffff96..6482d1928b2c 100644
--- a/pkgs/by-name/du/duckmarines/package.nix
+++ b/pkgs/by-name/du/duckmarines/package.nix
@@ -76,7 +76,20 @@ stdenv.mkDerivation rec {
     description = "Duck-themed action puzzle video game";
     platforms = lib.platforms.linux;
     hydraPlatforms = [ ];
-    license = lib.licenses.free;
+    license = with lib.licenses; [
+      # code
+      zlib
+
+      # assets
+      cc-by-sa-40
+      cc-by-nc-nd-40
+
+      # slam
+      mit
+
+      # tserial
+      unfree
+    ];
     downloadPage = "http://tangramgames.dk/games/duckmarines";
   };