diff --git a/jest/index.d.ts b/jest/index.d.ts
index f376ea5bcc..cb25dcc758 100644
--- a/jest/index.d.ts
+++ b/jest/index.d.ts
@@ -117,7 +117,7 @@ declare namespace jest {
         toBe(expected: any): void;
         toBeCalled(): void;
         toBeCalledWith(...args: any[]): void;
-        toBeCloseTo(expected: number, delta: number): void;
+        toBeCloseTo(expected: number, delta?: number): void;
         toBeDefined(): void;
         toBeFalsy(): void;
         toBeGreaterThan(expected: number): void;
diff --git a/jest/jest-tests.ts b/jest/jest-tests.ts
index 913a671fa1..4f54d44236 100644
--- a/jest/jest-tests.ts
+++ b/jest/jest-tests.ts
@@ -147,6 +147,10 @@ describe('compartion', function () {
     it('works sanely with simple decimals', function () {
         expect(0.2 + 0.1).toBeCloseTo(0.3, 5);
     });
+
+    it('works sanely with simple decimals and the default delta', function () {
+        expect(0.2 + 0.1).toBeCloseTo(0.3);
+    });
 });
 
 describe('toThrow API', function () {