diff --git a/pkgs/servers/dns/knot-resolver/default.nix b/pkgs/servers/dns/knot-resolver/default.nix
index aabfcd9796e4..f7a07acf04b4 100644
--- a/pkgs/servers/dns/knot-resolver/default.nix
+++ b/pkgs/servers/dns/knot-resolver/default.nix
@@ -3,6 +3,7 @@
 , runCommand, pkgconfig, meson, ninja, makeWrapper
 # build+runtime deps.
 , knot-dns, luajitPackages, libuv, gnutls, lmdb, systemd, dns-root-data
+, nghttp2
 # test-only deps.
 , cmocka, which, cacert
 , extraFeatures ? false /* catch-all if defaults aren't enough */
@@ -11,7 +12,7 @@ let # un-indented, over the whole file
 
 result = if extraFeatures then wrapped-full else unwrapped;
 
-inherit (stdenv.lib) optional optionals;
+inherit (stdenv.lib) optional optionals optionalString;
 lua = luajitPackages;
 
 unwrapped = stdenv.mkDerivation rec {
@@ -38,6 +39,11 @@ unwrapped = stdenv.mkDerivation rec {
     # ExecStart can't be overwritten in overrides.
     # We need that to use wrapped executable and correct config file.
     sed '/^ExecStart=/d' -i systemd/kresd@.service.in
+  ''
+    # some tests have issues with network sandboxing, apparently
+  + optionalString doInstallCheck ''
+    echo 'os.exit(77)' > daemon/lua/trust_anchors.test/bootstrap.test.lua
+    sed '/^[[:blank:]]*test_dstaddr,$/d' -i tests/config/doh2.test.lua
   '';
 
   preConfigure = ''
@@ -49,6 +55,7 @@ unwrapped = stdenv.mkDerivation rec {
   # http://knot-resolver.readthedocs.io/en/latest/build.html#requirements
   buildInputs = [ knot-dns lua.lua libuv gnutls lmdb ]
     ++ optional stdenv.isLinux systemd # passing sockets, sd_notify
+    ++ [ nghttp2 ]
     ## optional dependencies; TODO: libedit, dnstap
     ;
 
@@ -71,7 +78,7 @@ unwrapped = stdenv.mkDerivation rec {
   '';
 
   doInstallCheck = with stdenv; hostPlatform == buildPlatform;
-  installCheckInputs = [ cmocka which cacert lua.cqueues lua.basexx ];
+  installCheckInputs = [ cmocka which cacert lua.cqueues lua.basexx lua.http ];
   installCheckPhase = ''
     meson test --print-errorlogs
   '';