diff --git a/pkg/util/list.go b/pkg/util/list.go
index a64e0fcf34c..440a8bbba68 100644
--- a/pkg/util/list.go
+++ b/pkg/util/list.go
@@ -33,3 +33,7 @@ func (sl *StringList) Set(value string) error {
 	}
 	return nil
 }
+
+func (*StringList) Type() string {
+	return "stringList"
+}
diff --git a/pkg/util/net.go b/pkg/util/net.go
index 53e3c64e366..f36b1cae3fd 100644
--- a/pkg/util/net.go
+++ b/pkg/util/net.go
@@ -37,6 +37,10 @@ func (ip *IP) Set(value string) error {
 	return nil
 }
 
+func (*IP) Type() string {
+	return "ip"
+}
+
 // IPNet adapts net.IPNet for use as a flag.
 type IPNet net.IPNet
 
@@ -53,3 +57,7 @@ func (ipnet *IPNet) Set(value string) error {
 	*ipnet = IPNet(*n)
 	return nil
 }
+
+func (*IPNet) Type() string {
+	return "ipNet"
+}