diff --git a/knockout.mapping/knockout.mapping.d.ts b/knockout.mapping/knockout.mapping.d.ts
index f1489a1e80..69b6ccaffb 100644
--- a/knockout.mapping/knockout.mapping.d.ts
+++ b/knockout.mapping/knockout.mapping.d.ts
@@ -33,6 +33,8 @@ interface KnockoutMapping {
     fromJS(jsObject: any, targetOrOptions: any): any;
     fromJS(jsObject: any, inputOptions: any, target: any): any;
     fromJSON(jsonString: string): any;
+    fromJSON(jsonString: string, targetOrOptions: any): any;
+    fromJSON(jsonString: string, inputOptions: any, target: any): any;
     toJS(rootObject: any, options?: KnockoutMappingOptions): any;
     toJSON(rootObject: any, options?: KnockoutMappingOptions): any;
     defaultOptions(): KnockoutMappingOptions;