diff --git a/pkgs/servers/dns/knot-resolver/default.nix b/pkgs/servers/dns/knot-resolver/default.nix
index 7a6c9de885a..1d8896bfc10 100644
--- a/pkgs/servers/dns/knot-resolver/default.nix
+++ b/pkgs/servers/dns/knot-resolver/default.nix
@@ -30,6 +30,9 @@ unwrapped = stdenv.mkDerivation rec {
     sha256 = "b37ff9ceefbaa4e4527d183fb1bbb63e641d34d9889ce92715128bc1423c7ef4";
   };
 
+  # https://gitlab.labs.nic.cz/knot/knot-resolver/issues/496
+  postPatch = "sed '/prefill.test.lua/d' -i modules/meson.build";
+
   outputs = [ "out" "dev" ];
 
   preConfigure = ''