diff --git a/lib/puppet/type/firewall.rb b/lib/puppet/type/firewall.rb
index 8cf0cffd4..5712144ad 100644
--- a/lib/puppet/type/firewall.rb
+++ b/lib/puppet/type/firewall.rb
@@ -948,7 +948,7 @@
       DESC
     },
     ipset: {
-      type: 'Optional[Variant[Pattern[/^(?:!\s)?[\w\-_]+\s(?:src|dst)(?:,src|,dst)?$/], Array[Pattern[/^(?:!\s)?[\w\-_]+\s(?:src|dst)(?:,src|,dst)?$/]]]]',
+      type: 'Optional[Variant[Pattern[/^(?:!\s)?[\w\-:_]+\s(?:src|dst)(?:,src|,dst)?$/], Array[Pattern[/^(?:!\s)?[\w\-:_]+\s(?:src|dst)(?:,src|,dst)?$/]]]]',
       desc: <<-DESC
       Matches against the specified ipset list.
       Requires ipset kernel module. Will accept a single element or an array.