diff --git a/types/nock/index.d.ts b/types/nock/index.d.ts
index 8c6e4f2faf..91037b8e54 100644
--- a/types/nock/index.d.ts
+++ b/types/nock/index.d.ts
@@ -4,6 +4,7 @@
 //                 Horiuchi_H <https://github.com/horiuchi>
 //                 afharo <https://github.com/afharo>
 //                 Matt R. Wilson <https://github.com/mastermatt>
+//                 Garanzha Dmitriy <https://github.com/damour>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 /// <reference types="node" />
@@ -34,7 +35,7 @@ declare namespace nock {
 
     export var back: NockBack;
 
-    type HttpHeaders = { [key: string]: string | { (req: any, res: any, body: string): any; }; };
+    type HttpHeaders = { [key: string]: string | string[] | { (req: any, res: any, body: string): any; }; };
     type InterceptFunction = (
         uri: string | RegExp | { (uri: string): boolean; },
         requestBody?: string | RegExp | { (body: any): boolean; } | any,
diff --git a/types/nock/nock-tests.ts b/types/nock/nock-tests.ts
index 180c7a9c63..e81e3fd096 100644
--- a/types/nock/nock-tests.ts
+++ b/types/nock/nock-tests.ts
@@ -368,6 +368,12 @@ var scope = nock('http://www.headdy.com')
      'X-My-Headers': 'My Header value'
    });
 
+var scope = nock('http://www.headdy.com')
+    .get('/')
+    .reply(200, 'Hello World!', {
+        'X-My-Headers': ['My Header value 1', 'My Header value 2']
+    });
+
 var scope = nock('http://www.headdy.com')
    .get('/')
    .reply(200, 'Hello World!', {