diff --git a/cmd/headscale/cli/preauthkeys.go b/cmd/headscale/cli/preauthkeys.go
index 20c23aee..514866e0 100644
--- a/cmd/headscale/cli/preauthkeys.go
+++ b/cmd/headscale/cli/preauthkeys.go
@@ -142,17 +142,6 @@ var createPreAuthKeyCmd = &cobra.Command{
 
 		subnet, _ := cmd.Flags().GetString("subnet")
 
-		if subnet != "" {
-			ipPrefix, err := netaddr.ParseIPPrefix(subnet)
-			if err != nil {
-				ErrorOutput(err, fmt.Sprintf("Error parsing subnet: %s", err), output)
-
-				return
-			}
-
-			subnet = ipPrefix.String()
-		}
-
 		if !reusable && subnet == "" {
 			ip, _ := cmd.Flags().GetString("ip")
 			if ip != "" {
diff --git a/preauth_keys.go b/preauth_keys.go
index 5d15c472..01c54cc1 100644
--- a/preauth_keys.go
+++ b/preauth_keys.go
@@ -10,6 +10,7 @@ import (
 	v1 "github.com/juanfont/headscale/gen/go/headscale/v1"
 	"google.golang.org/protobuf/types/known/timestamppb"
 	"gorm.io/gorm"
+	"inet.af/netaddr"
 )
 
 const (
@@ -63,6 +64,15 @@ func (h *Headscale) CreatePreAuthKeyWithSubnet(
 		return nil, err
 	}
 
+	if subnet != "" {
+		ipPrefix, err := netaddr.ParseIPPrefix(subnet)
+		if err != nil {
+			return nil, err
+		}
+
+		subnet = ipPrefix.String()
+	}
+
 	key := PreAuthKey{
 		Key:         kstr,
 		NamespaceID: namespace.ID,