diff --git a/types/dwt/Dynamsoft.d.ts b/types/dwt/Dynamsoft.d.ts
index 65569f61b3..38ddc3ef49 100644
--- a/types/dwt/Dynamsoft.d.ts
+++ b/types/dwt/Dynamsoft.d.ts
@@ -27,6 +27,7 @@ interface dwtEnv {
     DynamicContainers: string[];
     DynamicDWTMap: {};
     GetWebTwain(cid: string): WebTwain;
+    IfInstallDWTModuleWithZIP: boolean;
     IfUpdateService: boolean;
     IfUseActiveXForIE10Plus: boolean;
     JSVersion: string;
diff --git a/types/dwt/index.d.ts b/types/dwt/index.d.ts
index 04f600367d..3650529393 100644
--- a/types/dwt/index.d.ts
+++ b/types/dwt/index.d.ts
@@ -4,6 +4,7 @@
 //                 Josh Hall <https://github.com/jbh>
 //                 Lincoln Hu <https://github.com/lincoln2018>
 //                 Tom Kent <https://github.com/Tom-Dynamsoft>
+//                 Dave Sueltenfuss <https://github.com/dsueltenfuss>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.4