diff --git a/db/models/public_key.go b/db/models/public_key.go
index a8c9252..f12a764 100644
--- a/db/models/public_key.go
+++ b/db/models/public_key.go
@@ -5,6 +5,6 @@ import "gorm.io/gorm"
 type PublicKey struct {
 	gorm.Model
 	UserID uint
-	Key    string
+	Key    string `gorm:"unique;not null"`
 	User   User
 }