diff --git a/types/mailcheck/index.d.ts b/types/mailcheck/index.d.ts
index 5c42ec02c6..bf181ee80c 100644
--- a/types/mailcheck/index.d.ts
+++ b/types/mailcheck/index.d.ts
@@ -2,7 +2,7 @@
 // Project: https://github.com/mailcheck/mailcheck
 // Definitions by: Paulo Cesar <https://github.com/pocesar>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
-// TypeScript Version: 2.3
+// TypeScript Version: 3.8
 
 /// <reference types="jquery" />
 
@@ -46,23 +46,31 @@ declare namespace MailcheckModule {
         full: string;
     }
 
-    export interface IOptions {
+    export interface IAsynchronousOptions {
         email: string;
         domains?: string[];
         secondLevelDomains?: string[];
         topLevelDomains?: string[];
         distanceFunction?: IDistanceFunction;
-        suggested?: ISuggested | IJQuerySuggested;
+        suggested: ISuggested | IJQuerySuggested;
         empty?: IEmpty | IJQueryEmpty;
     }
+    export interface ISynchronousOptions {
+        email: string;
+        domains?: string[];
+        secondLevelDomains?: string[];
+        topLevelDomains?: string[];
+        distanceFunction?: IDistanceFunction;
 
+    }
     export interface Static {
         defaultDomains: string[];
         defaultSecondLevelDomains: string[];
         defaultTopLevelDomains: string[];
         domainThreshold: number;
         topLevelThreshold: number;
-        run(opts: IOptions):void;
+        run(opts: IAsynchronousOptions):void;
+        run(opts: ISynchronousOptions):ISuggestion | undefined;
         suggest: ISuggestFunction;
         encodeEmail(email: string): string;
         splitEmail(email: string): ISplitEmail;
@@ -73,7 +81,8 @@ declare namespace MailcheckModule {
 }
 
 interface JQuery {
-    mailcheck(opts: MailcheckModule.IOptions): void;
+    mailcheck(opts: MailcheckModule.IAsynchronousOptions):void;
+    mailcheck(opts: MailcheckModule.ISynchronousOptions):MailcheckModule.ISuggestion | void;
 }
 
 declare module 'mailcheck' {
diff --git a/types/mailcheck/mailcheck-tests.ts b/types/mailcheck/mailcheck-tests.ts
index 971ecf8218..67081002bb 100644
--- a/types/mailcheck/mailcheck-tests.ts
+++ b/types/mailcheck/mailcheck-tests.ts
@@ -18,6 +18,8 @@ $('#email').on('blur', function() {
         distanceFunction: superStringDistance,  // optional
         suggested: function(element: JQuery, suggestion: MailcheckModule.ISuggestion) {
           // callback code
+          element; // $ExpectType JQuery<HTMLElement>
+          suggestion; // $ExpectType ISuggestion
         },
         empty: function(element: JQuery) {
           // callback code
@@ -33,6 +35,7 @@ Mailcheck.run({
     distanceFunction: superStringDistance,  // optional
     suggested: function(suggestion: MailcheckModule.ISuggestion) {
       // callback code
+      suggestion; // $ExpectType ISuggestion
     },
     empty: function() {
       // callback code
@@ -47,9 +50,18 @@ MC.run({
     distanceFunction: superStringDistance,  // optional
     suggested: function(suggested: MailcheckModule.ISuggestion) {
       // callback code
-      suggested.address === '' && suggested.full === '' && suggested.domain === '';
+      suggested; // $ExpectType ISuggestion
     },
     empty: function() {
       // callback code
     }
-});
\ No newline at end of file
+});
+
+const result3 = MC.run({
+    email: 'nonoptional@example.com',
+    domains: domains,                       // optional
+    secondLevelDomains: secondLevelDomains, // optional
+    topLevelDomains: topLevelDomains,       // optional
+    distanceFunction: superStringDistance,  // optional
+});
+result3; // $ExpectType ISuggestion | undefined
\ No newline at end of file