diff --git a/fibonacci/fibonacci.js b/fibonacci/fibonacci.js
index 65b28bb..b2d7689 100644
--- a/fibonacci/fibonacci.js
+++ b/fibonacci/fibonacci.js
@@ -1,5 +1,13 @@
-var fibonacci = function() {
+const fibonacci = function(count) {
+  if (count < 0) return "OOPS";
+  let a = 0;
+  let b = 1;
+  for (let i = 1; i < count; i++) {
+    const temp = b;
+    b = a + b;
+    a = temp;
+  }
+  return b;
+};
 
-}
-
-module.exports = fibonacci
+module.exports = fibonacci;
diff --git a/fibonacci/fibonacci.spec.js b/fibonacci/fibonacci.spec.js
index 956e418..9146992 100644
--- a/fibonacci/fibonacci.spec.js
+++ b/fibonacci/fibonacci.spec.js
@@ -1,25 +1,25 @@
-var fibonacci = require('./fibonacci')
+const fibonacci = require("./fibonacci");
 
-describe('fibonacci', function() {
-  it('works', function() {
+describe("fibonacci", () => {
+  it("works", () => {
     expect(fibonacci(4)).toEqual(3);
   });
-  xit('works', function() {
+  it("works", () => {
     expect(fibonacci(6)).toEqual(8);
   });
-  xit('works', function() {
+  it("works", () => {
     expect(fibonacci(10)).toEqual(55);
   });
-  xit('works', function() {
+  it("works", () => {
     expect(fibonacci(15)).toEqual(610);
   });
-  xit('works', function() {
+  it("works", () => {
     expect(fibonacci(25)).toEqual(75025);
   });
-  xit('doesn\'t accept negatives', function() {
+  it("doesn't accept negatives", () => {
     expect(fibonacci(-25)).toEqual("OOPS");
   });
-  xit('DOES accept strings', function() {
+  it("DOES accept strings", () => {
     expect(fibonacci("8")).toEqual(21);
   });
 });