diff --git a/pdns_recursor.cc b/pdns_recursor.cc
index 44a5ffa20..ed64c16a8 100644
--- a/pdns_recursor.cc
+++ b/pdns_recursor.cc
@@ -3159,6 +3159,7 @@ static int serviceMain(int argc, char*argv[])
   SyncRes::s_serverdownthrottletime=::arg().asNum("server-down-throttle-time");
   SyncRes::s_serverID=::arg()["server-id"];
   SyncRes::s_maxqperq=::arg().asNum("max-qperq");
+  SyncRes::s_maxnsaddressqperq=::arg().asNum("max-ns-address-qperq");
   SyncRes::s_maxtotusec=1000*::arg().asNum("max-total-msec");
   SyncRes::s_maxdepth=::arg().asNum("max-recursion-depth");
   SyncRes::s_rootNXTrust = ::arg().mustDo( "root-nx-trust");
@@ -3657,6 +3658,7 @@ int main(int argc, char **argv)
     ::arg().set("edns-outgoing-bufsize", "Outgoing EDNS buffer size")="1680";
     ::arg().set("minimum-ttl-override", "Set under adverse conditions, a minimum TTL")="0";
     ::arg().set("max-qperq", "Maximum outgoing queries per query")="50";
+    ::arg().set("max-ns-address-qperq", "Maximum outgoing NS address queries per query")="10";
     ::arg().set("max-total-msec", "Maximum total wall-clock time per query in milliseconds, 0 for unlimited")="7000";
     ::arg().set("max-recursion-depth", "Maximum number of internal recursion calls per query, 0 for unlimited")="40";
     ::arg().set("max-udp-queries-per-round", "Maximum number of UDP queries processed per recvmsg() round, before returning back to normal processing")="10000";
diff --git a/test-syncres_cc.cc b/test-syncres_cc.cc
index 00c85441b..29886cccd 100644
--- a/test-syncres_cc.cc
+++ b/test-syncres_cc.cc
@@ -135,7 +135,8 @@ static void init(bool debug=false)
   t_RC = std::unique_ptr<MemRecursorCache>(new MemRecursorCache());
 
   SyncRes::s_maxqperq = 50;
-  SyncRes::s_maxtotusec = 1000*7000;
+  SyncRes::s_maxnsaddressqperq = 10;
+  SyncRes::s_maxtotusec = 1000 * 7000;
   SyncRes::s_maxdepth = 40;
   SyncRes::s_maxnegttl = 3600;
   SyncRes::s_maxcachettl = 86400;
@@ -10512,6 +10513,48 @@ BOOST_AUTO_TEST_CASE(test_getDSRecords_multialgo_prefer_gost_over_sha1) {
 }
 #endif // HAVE_BOTAN110
 
+BOOST_AUTO_TEST_CASE(test_completely_flawed_big_nsset)
+{
+  std::unique_ptr<SyncRes> sr;
+  initSR(sr);
+
+  primeHints();
+
+  const DNSName target("powerdns.com.");
+  size_t queriesCount = 0;
+
+  sr->setAsyncCallback([&queriesCount, target](const ComboAddress& ip, const DNSName& domain, int type, bool doTCP, bool sendRDQuery, int EDNS0Level, struct timeval* now, boost::optional<Netmask>& srcmask, boost::optional<const ResolveContext&> context, std::shared_ptr<RemoteLogger> outgoingLogger, LWResult* res, bool* chained) {
+    queriesCount++;
+
+    if (isRootServer(ip) && domain == target) {
+      setLWResult(res, 0, false, false, true);
+      // 20 NS records
+      for (int i = 0; i < 20; i++)  {
+        string n = string("pdns-public-ns") + std::to_string(i) + string(".powerdns.com.");
+        addRecordToLW(res, domain, QType::NS, n, DNSResourceRecord::AUTHORITY, 172800);
+      }
+      return 1;
+    }
+    else if (domain.toString().length() > 14 && domain.toString().substr(0, 14) == "pdns-public-ns") {
+      setLWResult(res, 0, true, false, true);
+      addRecordToLW(res, ".", QType::SOA, "a.root-servers.net. nstld.verisign-grs.com. 2017032800 1800 900 604800 86400", DNSResourceRecord::AUTHORITY, 86400);
+      return 1;
+    }
+    return 0;
+  });
+
+  vector<DNSRecord> ret;
+  try {
+    sr->beginResolve(target, QType(QType::A), QClass::IN, ret);
+    BOOST_CHECK(0);
+  } catch (const ImmediateServFailException& ex) {
+      BOOST_CHECK_EQUAL(ret.size(), 0U);
+      // one query to get NSs, then A and AAAA for each NS, 5th NS hits the limit
+      // limit is reduced to 5, because zone publishes many (20) NS
+    BOOST_CHECK_EQUAL(queriesCount, 11);
+  }
+}
+
 /*
 // cerr<<"asyncresolve called to ask "<<ip.toStringWithPort()<<" about "<<domain.toString()<<" / "<<QType(type).getName()<<" over "<<(doTCP ? "TCP" : "UDP")<<" (rd: "<<sendRDQuery<<", EDNS0 level: "<<EDNS0Level<<")"<<endl;
 
diff --git a/syncres.cc b/syncres.cc
index c62099ba4..a0339a1cf 100644
--- a/syncres.cc
+++ b/syncres.cc
@@ -49,6 +49,7 @@ SyncRes::LogMode SyncRes::s_lm;
 unsigned int SyncRes::s_maxnegttl;
 unsigned int SyncRes::s_maxcachettl;
 unsigned int SyncRes::s_maxqperq;
+unsigned int SyncRes::s_maxnsaddressqperq;
 unsigned int SyncRes::s_maxtotusec;
 unsigned int SyncRes::s_maxdepth;
 unsigned int SyncRes::s_minimumTTL;
@@ -709,7 +710,7 @@ struct speedOrderCA
 
 /** This function explicitly goes out for A or AAAA addresses
 */
-vector<ComboAddress> SyncRes::getAddrs(const DNSName &qname, unsigned int depth, set<GetBestNSAnswer>& beenthere, bool cacheOnly)
+vector<ComboAddress> SyncRes::getAddrs(const DNSName &qname, unsigned int depth, set<GetBestNSAnswer>& beenthere, bool cacheOnly, unsigned int& addressQueriesForNS)
 {
   typedef vector<DNSRecord> res_t;
   res_t res;
@@ -721,6 +722,7 @@ vector<ComboAddress> SyncRes::getAddrs(const DNSName &qname, unsigned int depth,
   bool oldCacheOnly = d_cacheonly;
   bool oldRequireAuthData = d_requireAuthData;
   bool oldValidationRequested = d_DNSSECValidationRequested;
+  const unsigned int startqueries = d_outqueries;
   d_requireAuthData = false;
   d_DNSSECValidationRequested = false;
   d_cacheonly = cacheOnly;
@@ -770,6 +772,10 @@ vector<ComboAddress> SyncRes::getAddrs(const DNSName &qname, unsigned int depth,
     }
   }
 
+  if (ret.empty() && d_outqueries > startqueries) {
+    // We did 1 or more outgoing queries to resolve this NS name but returned empty handed
+    addressQueriesForNS++;
+  }
   d_requireAuthData = oldRequireAuthData;
   d_DNSSECValidationRequested = oldValidationRequested;
   d_cacheonly = oldCacheOnly;
@@ -1477,13 +1483,13 @@ bool SyncRes::nameserverIPBlockedByRPZ(const DNSFilterEngine& dfe, const ComboAd
   return false;
 }
 
-vector<ComboAddress> SyncRes::retrieveAddressesForNS(const std::string& prefix, const DNSName& qname, vector<DNSName >::const_iterator& tns, const unsigned int depth, set<GetBestNSAnswer>& beenthere, const vector<DNSName >& rnameservers, NsSet& nameservers, bool& sendRDQuery, bool& pierceDontQuery, bool& flawedNSSet, bool cacheOnly)
+vector<ComboAddress> SyncRes::retrieveAddressesForNS(const std::string& prefix, const DNSName& qname, vector<DNSName >::const_iterator& tns, const unsigned int depth, set<GetBestNSAnswer>& beenthere, const vector<DNSName >& rnameservers, NsSet& nameservers, bool& sendRDQuery, bool& pierceDontQuery, bool& flawedNSSet, bool cacheOnly, unsigned int& retrieveAddressesForNS)
 {
   vector<ComboAddress> result;
 
   if(!tns->empty()) {
     LOG(prefix<<qname<<": Trying to resolve NS '"<<*tns<< "' ("<<1+tns-rnameservers.begin()<<"/"<<(unsigned int)rnameservers.size()<<")"<<endl);
-    result = getAddrs(*tns, depth+2, beenthere, cacheOnly);
+    result = getAddrs(*tns, depth+2, beenthere, cacheOnly, retrieveAddressesForNS);
     pierceDontQuery=false;
   }
   else {
@@ -2727,10 +2733,24 @@ int SyncRes::doResolveAt(NsSet &nameservers, DNSName auth, bool flawedNSSet, con
 
   LOG(endl);
 
+  unsigned int addressQueriesForNS = 0;
   for(;;) { // we may get more specific nameservers
     vector<DNSName > rnameservers = shuffleInSpeedOrder(nameservers, doLog() ? (prefix+qname.toString()+": ") : string() );
 
+    // We allow s_maxnsaddressqperq (default 10) queries with empty responses when resolving NS names.
+    // If a zone publishes many (more than s_maxnsaddressqperq) NS records, we allow less.
+    // This is to "punish" zones that publish many non-resolving NS names.
+    // We always allow 5 NS name resolving attempts with empty results.
+    unsigned int nsLimit = s_maxnsaddressqperq;
+    if (rnameservers.size() > nsLimit) {
+      int newLimit = static_cast<int>(nsLimit) - (rnameservers.size() - nsLimit);
+      nsLimit = std::max(5, newLimit);
+    }
+
     for(auto tns=rnameservers.cbegin();;++tns) {
+      if (addressQueriesForNS >= nsLimit) {
+        throw ImmediateServFailException(std::to_string(nsLimit)+" (adjusted max-ns-address-qperq) or more queries with empty results for NS addresses sent resolving "+qname.toLogString());
+      }
       if(tns==rnameservers.cend()) {
         LOG(prefix<<qname<<": Failed to resolve via any of the "<<(unsigned int)rnameservers.size()<<" offered NS at level '"<<auth<<"'"<<endl);
         if(!auth.isRoot() && flawedNSSet) {
@@ -2782,7 +2802,7 @@ int SyncRes::doResolveAt(NsSet &nameservers, DNSName auth, bool flawedNSSet, con
       }
       else {
         /* if tns is empty, retrieveAddressesForNS() knows we have hardcoded servers (i.e. "forwards") */
-        remoteIPs = retrieveAddressesForNS(prefix, qname, tns, depth, beenthere, rnameservers, nameservers, sendRDQuery, pierceDontQuery, flawedNSSet, cacheOnly);
+        remoteIPs = retrieveAddressesForNS(prefix, qname, tns, depth, beenthere, rnameservers, nameservers, sendRDQuery, pierceDontQuery, flawedNSSet, cacheOnly, addressQueriesForNS);
 
         if(remoteIPs.empty()) {
           LOG(prefix<<qname<<": Failed to get IP for NS "<<*tns<<", trying next if available"<<endl);
diff --git a/syncres.hh b/syncres.hh
index 29eed2191..b06ef252e 100644
--- a/syncres.hh
+++ b/syncres.hh
@@ -712,6 +712,7 @@ public:
   static string s_serverID;
   static unsigned int s_minimumTTL;
   static unsigned int s_maxqperq;
+  static unsigned int s_maxnsaddressqperq;
   static unsigned int s_maxtotusec;
   static unsigned int s_maxdepth;
   static unsigned int s_maxnegttl;
@@ -781,13 +782,13 @@ private:
 
   inline vector<DNSName> shuffleInSpeedOrder(NsSet &nameservers, const string &prefix);
   bool moreSpecificThan(const DNSName& a, const DNSName &b) const;
-  vector<ComboAddress> getAddrs(const DNSName &qname, unsigned int depth, set<GetBestNSAnswer>& beenthere, bool cacheOnly);
+  vector<ComboAddress> getAddrs(const DNSName &qname, unsigned int depth, set<GetBestNSAnswer>& beenthere, bool cacheOnly, unsigned int& addressQueriesForNS);
 
   bool nameserversBlockedByRPZ(const DNSFilterEngine& dfe, const NsSet& nameservers);
   bool nameserverIPBlockedByRPZ(const DNSFilterEngine& dfe, const ComboAddress&);
   bool throttledOrBlocked(const std::string& prefix, const ComboAddress& remoteIP, const DNSName& qname, const QType& qtype, bool pierceDontQuery);
 
-  vector<ComboAddress> retrieveAddressesForNS(const std::string& prefix, const DNSName& qname, vector<DNSName >::const_iterator& tns, const unsigned int depth, set<GetBestNSAnswer>& beenthere, const vector<DNSName >& rnameservers, NsSet& nameservers, bool& sendRDQuery, bool& pierceDontQuery, bool& flawedNSSet, bool cacheOnly);
+  vector<ComboAddress> retrieveAddressesForNS(const std::string& prefix, const DNSName& qname, vector<DNSName >::const_iterator& tns, const unsigned int depth, set<GetBestNSAnswer>& beenthere, const vector<DNSName >& rnameservers, NsSet& nameservers, bool& sendRDQuery, bool& pierceDontQuery, bool& flawedNSSet, bool cacheOnly, unsigned int& addressQueriesForNS);
 
   RCode::rcodes_ updateCacheFromRecords(unsigned int depth, LWResult& lwr, const DNSName& qname, const QType& qtype, const DNSName& auth, bool wasForwarded, const boost::optional<Netmask>, vState& state, bool& needWildcardProof, bool& gatherWildcardProof, unsigned int& wildcardLabelsCount, bool sendRDQuery);
   bool processRecords(const std::string& prefix, const DNSName& qname, const QType& qtype, const DNSName& auth, LWResult& lwr, const bool sendRDQuery, vector<DNSRecord>& ret, set<DNSName>& nsset, DNSName& newtarget, DNSName& newauth, bool& realreferral, bool& negindic, vState& state, const bool needWildcardProof, const bool gatherwildcardProof, const unsigned int wildcardLabelsCount);
