diff --git a/types/sequelize/index.d.ts b/types/sequelize/index.d.ts
index d0ed8efc50..d20bd83b86 100644
--- a/types/sequelize/index.d.ts
+++ b/types/sequelize/index.d.ts
@@ -1200,7 +1200,7 @@ declare namespace sequelize {
          *  Attribute name for the relation
          */
         name?: string;
-
+        unique?: boolean | string;
     }
 
     /**