diff --git a/__main__.py b/__main__.py
index 8142620..b001537 100644
--- a/__main__.py
+++ b/__main__.py
@@ -331,14 +331,14 @@ class Registry(object):
 
         if zone.endswith("ip6.arpa."):
             # ipv6 reverse zone -> inet6num
-            return self._generate_reverseV6_zone(zone, TTL)
+            return list(set(self._generate_reverseV6_zone(zone, TTL)))
 
         elif zone.endswith("in-addr.arpa."):
             # ipv4 reverse zone -> inetnum
-            return self._generate_reverseV4_zone(zone, TTL)
+            return list(set(self._generate_reverseV4_zone(zone, TTL)))
         else:
             # other zone -> dns
-            return self._generate_forward_zone(zone, TTL)
+            return list(set(self._generate_forward_zone(zone, TTL)))
 
 
 if __name__ == "__main__":