diff --git a/types/jasmine-given/index.d.ts b/types/jasmine-given/index.d.ts
index df2fe424a9..1275cf9738 100644
--- a/types/jasmine-given/index.d.ts
+++ b/types/jasmine-given/index.d.ts
@@ -1,7 +1,9 @@
 // Type definitions for jasmine-given 2.6
 // Project: https://github.com/searls/jasmine-given
 // Definitions by: Shai Reznik <https://github.com/shairez>
+//                 Dmitry Efimenko <https://github.com/DmitryEfimenko>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
+// TypeScript Version: 2.1
 
 /** Action method that should be called when the async work is complete */
 interface DoneFn {
@@ -11,9 +13,9 @@ interface DoneFn {
   fail: (message?: Error | string) => void;
 }
 
-declare function Given(func: (done?: DoneFn) => void): void;
-declare function When(func: (done?: DoneFn) => void): void;
-declare function Then(func: (done?: DoneFn) => void): void;
-declare function Then(label: string, func: (done?: DoneFn) => void): void;
-declare function And(func: (done?: DoneFn) => void): void;
-declare function Invariant(func: (done?: DoneFn) => void): void;
+declare function Given(func: (done: DoneFn) => void): void;
+declare function When(func: (done: DoneFn) => void): void;
+declare function Then(func: (done: DoneFn) => void): void;
+declare function Then(label: string, func: (done: DoneFn) => void): void;
+declare function And(func: (done: DoneFn) => void): void;
+declare function Invariant(func: (done: DoneFn) => void): void;
diff --git a/types/jasmine-given/jasmine-given-tests.ts b/types/jasmine-given/jasmine-given-tests.ts
index 10a6b824fe..0c2fd4fb67 100644
--- a/types/jasmine-given/jasmine-given-tests.ts
+++ b/types/jasmine-given/jasmine-given-tests.ts
@@ -11,61 +11,41 @@ And(() => { });
 Invariant(() => { });
 
 Given((done) => {
-  if (done) {
-    done();
-  }
+  done();
 });
 
 When((done) => {
-  if (done) {
-    done();
-  }
+  done();
 });
 
 Then('expected condition 2', (done) => {
-  if (done) {
-    done();
-  }
+  done();
 });
 
 And((done) => {
-  if (done) {
-    done();
-  }
+  done();
 });
 
 Invariant((done) => {
-  if (done) {
-    done();
-  }
+  done();
 });
 
 Given((done) => {
-  if (done) {
-    done.fail();
-  }
+  done.fail();
 });
 
 When((done) => {
-  if (done) {
-    done.fail();
-  }
+  done.fail();
 });
 
 Then('expected condition 2', (done) => {
-  if (done) {
-    done.fail();
-  }
+  done.fail();
 });
 
 And((done) => {
-  if (done) {
-    done.fail();
-  }
+  done.fail();
 });
 
 Invariant((done) => {
-  if (done) {
-    done.fail();
-  }
+  done.fail();
 });