diff --git a/lib/rubocop/cop/custom/ip_ranges.rb b/lib/rubocop/cop/custom/ip_ranges.rb
index 9748ed7..014118d 100644
--- a/lib/rubocop/cop/custom/ip_ranges.rb
+++ b/lib/rubocop/cop/custom/ip_ranges.rb
@@ -75,7 +75,7 @@ def read_node_ips(value)
         end
 
         def normalise_list(ips)
-          ips.sort_by(&IPAddr.method(:new))
+          ips.uniq.sort_by(&IPAddr.method(:new))
         end
 
         def register_offense(node, new_ips, **params)