diff --git a/nsupdate/main/dnstools.py b/nsupdate/main/dnstools.py
index ce30430..4daff10 100644
--- a/nsupdate/main/dnstools.py
+++ b/nsupdate/main/dnstools.py
@@ -28,6 +28,7 @@ import random
 import struct
 
 import dns.inet
+import dns.message
 import dns.name
 import dns.resolver
 import dns.query
@@ -256,7 +257,7 @@ def query_ns(fqdn, rdtype, prefer_primary=False):
         ip = str(list(answer)[0])
         logger.debug("query: %s answer: %s" % (fqdn, ip))
         return ip
-    except (dns.resolver.Timeout, dns.resolver.NoNameservers) as e:  # socket.error also?
+    except (dns.resolver.Timeout, dns.resolver.NoNameservers, dns.message.UnknownTSIGKey) as e:  # socket.error also?
         logger.warning("error when querying for name '%s' in zone '%s' with rdtype '%s' [%s]." % (
                        fqdn.host, origin, rdtype, str(e)))
         set_ns_availability(origin, False)
diff --git a/nsupdate/main/models.py b/nsupdate/main/models.py
index e04d5f3..5cc69ca 100644
--- a/nsupdate/main/models.py
+++ b/nsupdate/main/models.py
@@ -7,6 +7,7 @@ import time
 import base64
 
 import dns.resolver
+import dns.message
 
 from django.db import models
 from django.contrib.auth import get_user_model
@@ -288,7 +289,8 @@ class Host(models.Model):
             return dnstools.query_ns(self.get_fqdn(), record)
         except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer):
             return None
-        except (dns.resolver.NoNameservers, dns.resolver.Timeout, dnstools.NameServerNotAvailable):
+        except (dns.resolver.NoNameservers, dns.resolver.Timeout, dnstools.NameServerNotAvailable,
+                dns.message.UnknownTSIGKey):
             return _('error')
 
     def get_ipv4(self):