diff --git a/pkgs/servers/dns/knot-resolver/default.nix b/pkgs/servers/dns/knot-resolver/default.nix
index 715e32874ac..6ccd849e1c8 100644
--- a/pkgs/servers/dns/knot-resolver/default.nix
+++ b/pkgs/servers/dns/knot-resolver/default.nix
@@ -27,11 +27,12 @@ unwrapped = stdenv.mkDerivation rec {
 
   # http://knot-resolver.readthedocs.io/en/latest/build.html#requirements
   buildInputs = [ knot-dns luajit libuv gnutls nettle lmdb ]
-    ++ optional doCheck cmocka
     ++ optional stdenv.isLinux systemd # sd_notify
     ## optional dependencies; TODO: libedit, dnstap
     ;
 
+  checkInputs = [ cmocka ];
+
   makeFlags = [
     "PREFIX=$(out)"
     "ROOTHINTS=${dns-root-data}/root.hints"