diff --git a/types/cosmiconfig/cosmiconfig-tests.ts b/types/cosmiconfig/cosmiconfig-tests.ts
index 632569c6f9..73010d01ac 100644
--- a/types/cosmiconfig/cosmiconfig-tests.ts
+++ b/types/cosmiconfig/cosmiconfig-tests.ts
@@ -11,6 +11,8 @@ const explorer = cosmiconfig("yourModuleName", {
   ignoreEmptySearchPlaces: false,
 });
 
+const explorer2 = cosmiconfig("yourModuleName");
+
 Promise.all([
   explorer.search(path.join(__dirname)),
   explorer.searchSync(path.join(__dirname)),
diff --git a/types/cosmiconfig/index.d.ts b/types/cosmiconfig/index.d.ts
index bdafc922ec..e8fd3fed17 100644
--- a/types/cosmiconfig/index.d.ts
+++ b/types/cosmiconfig/index.d.ts
@@ -2,6 +2,7 @@
 // Project: https://github.com/davidtheclark/cosmiconfig
 // Definitions by: ozum <https://github.com/ozum>
 //                 szeck87 <https://github.com/szeck87>
+//                 saadq <https://github.com/saadq>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 // TypeScript Version: 2.2
 
@@ -55,4 +56,4 @@ export interface ExplorerOptions {
   ignoreEmptySearchPlaces?: boolean;
 }
 
-export default function cosmiconfig(moduleName: string, options: ExplorerOptions): Explorer;
+export default function cosmiconfig(moduleName: string, options?: ExplorerOptions): Explorer;