diff --git a/typescript/core/base.ts b/typescript/core/base.ts
index d0e26dc1d8..68d82b9b36 100644
--- a/typescript/core/base.ts
+++ b/typescript/core/base.ts
@@ -235,7 +235,7 @@ export interface _base {
 
     init: () => void;
 
-    has: (obj: object, keys: string[]) => boolean;
+    has: (obj: object, keys: string|string[]) => boolean;
 
     freeze: <T>(value: T) => T;
 
@@ -261,7 +261,7 @@ export interface _base {
 
     isDeepMatch: (object: any, attrs: any) => boolean;
 
-    contains: (obj: any[], target: any, fromIndex: number) => number;
+    contains: (obj: any[], target: any, fromIndex?: number) => number;
 
     deepContains: (obj: any[], copy: any) => number;
 
diff --git a/typescript/core/i18n.ts b/typescript/core/i18n.ts
index 2e4960158f..95aa195846 100644
--- a/typescript/core/i18n.ts
+++ b/typescript/core/i18n.ts
@@ -1,4 +1,4 @@
-export declare type _addI18n = (v: string) => string;
+export declare type _addI18n = (v: string | object) => string;
 
 export declare type _i18nText = (key: string, ..._args: any[]) => string;