diff --git a/mdb/management/commands/zone-sync.py b/mdb/management/commands/zone-sync.py
index bc3a838..29b39c4 100644
--- a/mdb/management/commands/zone-sync.py
+++ b/mdb/management/commands/zone-sync.py
@@ -46,7 +46,7 @@ class Command(BaseCommand):
 
         # do the binaries exist?
         for f in (self.checkzone_bin, self.bind_bin):
-            if not os.path.isfile(f):
+            if not os.path.isfile(f) and not debug:
                 print("ERROR: no such file %s, exiting..." % f)
                 if not debug:
                     sys.exit(1)
diff --git a/mdb/models.py b/mdb/models.py
index 969b530..eb3f3f1 100644
--- a/mdb/models.py
+++ b/mdb/models.py
@@ -93,7 +93,7 @@ class Domain(models.Model):
         if self.domain_ipaddr is not None:
             content += "@\tIN\tA\t%s\n" % self.domain_ipaddr
 
-        if self.domain_ip6addr is not None:
+        if self.domain_ip6addr:
             content += "@\tIN\tAAAA\t%s\n" % self.domain_ip6addr
 
         content += "; SRV records\n"