diff --git a/foundations/object_basics/03_fibonacci/README.md b/foundations/object_basics/03_fibonacci/README.md
index 77b62de3348..35053046c39 100644
--- a/foundations/object_basics/03_fibonacci/README.md
+++ b/foundations/object_basics/03_fibonacci/README.md
@@ -2,11 +2,11 @@
 
 Create a function that returns a specific member of the Fibonacci sequence (series of numbers in which each number is the sum of the two preceding numbers). To learn more about Fibonacci sequences, go to: https://en.wikipedia.org/wiki/Fibonacci_sequence
 
-In this exercise, the Fibonacci sequence used is 1, 1, 2, 3, 5, 8, etc. (i.e. starting at 1, not 0).
+In this exercise, the Fibonacci sequence used is 1, 1, 2, 3, 5, 8, etc. (i.e. starting at 1, not 0):
 
 ```javascript
 fibonacci(4); // returns the 4th member of the series: 3  (1, 1, 2, 3)
 fibonacci(6); // returns 8
 ```
 
-If given a negative number, the function should return `"OOPS"`.
\ No newline at end of file
+If given a negative number, `NaN`, or not a number type at all, the function should return `"OOPS"`, i.e. only proceed with positive numbers.
diff --git a/foundations/object_basics/03_fibonacci/fibonacci.spec.js b/foundations/object_basics/03_fibonacci/fibonacci.spec.js
index de632d833f2..8f2df2301e9 100644
--- a/foundations/object_basics/03_fibonacci/fibonacci.spec.js
+++ b/foundations/object_basics/03_fibonacci/fibonacci.spec.js
@@ -22,16 +22,12 @@ describe('fibonacci', () => {
   test.skip('doesn\'t accept negatives', () => {
     expect(fibonacci(-25)).toBe("OOPS");
   });
-  test.skip('DOES accept strings', () => {
-    expect(fibonacci("0")).toBe(0);
+  test.skip('doesn\'t accept NaN', () => {
+    expect(fibonacci(NaN)).toBe("OOPS");
   });
-  test.skip('DOES accept strings', () => {
-    expect(fibonacci("1")).toBe(1);
+  test.skip('doesn\'t accept non-numbers types', () => {
+    expect(fibonacci("0")).toBe("OOPS");
+    expect(fibonacci([])).toBe("OOPS");
+    expect(fibonacci({})).toBe("OOPS");
   });
-  test.skip('DOES accept strings', () => {
-    expect(fibonacci("2")).toBe(1);
-  });
-  test.skip('DOES accept strings', () => {
-    expect(fibonacci("8")).toBe(21);
-  });
-});
+})
diff --git a/foundations/object_basics/03_fibonacci/solution/fibonacci-solution.js b/foundations/object_basics/03_fibonacci/solution/fibonacci-solution.js
index 1327ce92c5e..642c8cbc532 100644
--- a/foundations/object_basics/03_fibonacci/solution/fibonacci-solution.js
+++ b/foundations/object_basics/03_fibonacci/solution/fibonacci-solution.js
@@ -1,15 +1,13 @@
-const fibonacci = function(countArg) {
-    // checks argument's type and makes sure we use 
+const fibonacci = function(count) {
+    // checks argument's type and makes sure we use
     // a number throughout rest of function.
-    let count
-    if (typeof countArg !== 'number') {
-        count = parseInt(countArg)
-    } else {
-        count = countArg
+    if (typeof count !== 'number' || count < 0 || Number.isNaN(count)) {
+        return "OOPS";
+    }
+    
+    if (count === 0) {
+        return 0;
     }
-
-    if (count < 0) return "OOPS";
-    if (count == 0) return 0;
 
     let firstPrev = 1;
     let secondPrev = 0;
@@ -21,7 +19,6 @@ const fibonacci = function(countArg) {
     }
 
     return firstPrev;
-
 };
 
 // Another way to do it is by using an iterative approach with an array containing two values, 0 and 1.
diff --git a/foundations/object_basics/03_fibonacci/solution/fibonacci-solution.spec.js b/foundations/object_basics/03_fibonacci/solution/fibonacci-solution.spec.js
index fdb0badfac6..15338c71e63 100644
--- a/foundations/object_basics/03_fibonacci/solution/fibonacci-solution.spec.js
+++ b/foundations/object_basics/03_fibonacci/solution/fibonacci-solution.spec.js
@@ -22,16 +22,12 @@ describe('fibonacci', () => {
   test('doesn\'t accept negatives', () => {
     expect(fibonacci(-25)).toBe("OOPS");
   });
-  test('DOES accept strings', () => {
-    expect(fibonacci("0")).toBe(0);
+  test('doesn\'t accept NaN', () => {
+    expect(fibonacci(NaN)).toBe("OOPS");
   });
-  test('DOES accept strings', () => {
-    expect(fibonacci("1")).toBe(1);
+  test('doesn\'t accept non-numbers types', () => {
+    expect(fibonacci("0")).toBe("OOPS");
+    expect(fibonacci([])).toBe("OOPS");
+    expect(fibonacci({})).toBe("OOPS");
   });
-  test('DOES accept strings', () => {
-    expect(fibonacci("2")).toBe(1);
-  });
-  test('DOES accept strings', () => {
-    expect(fibonacci("8")).toBe(21);
-  });
-});
\ No newline at end of file
+})