diff --git a/preauth_keys.go b/preauth_keys.go
index a1107481..4494dda1 100644
--- a/preauth_keys.go
+++ b/preauth_keys.go
@@ -102,7 +102,7 @@ func (h *Headscale) DestroyPreAuthKey(pak *PreAuthKey) error {
 	return nil
 }
 
-// MarkExpirePreAuthKey marks a PreAuthKey as expired
+// MarkExpirePreAuthKey marks a PreAuthKey as expired.
 func (h *Headscale) ExpirePreAuthKey(k *PreAuthKey) error {
 	if err := h.db.Model(&k).Update("Expiration", time.Now()).Error; err != nil {
 		return err