diff --git a/pkgs/servers/u9fs/default.nix b/pkgs/servers/u9fs/default.nix
index 9056b4791672..cb85a972e034 100644
--- a/pkgs/servers/u9fs/default.nix
+++ b/pkgs/servers/u9fs/default.nix
@@ -19,7 +19,7 @@ stdenv.mkDerivation {
   meta = with lib; {
     description = "Serve 9P from Unix";
     homepage = "http://p9f.org/magic/man2html?man=u9fs&sect=4";
-    license = licenses.free;
+    license = licenses.dtoa;
     maintainers = [ maintainers.ehmry ];
     platforms = platforms.unix;
     mainProgram = "u9fs";