diff --git a/10_fibonacci/solution/fibonacci-solution.js b/10_fibonacci/solution/fibonacci-solution.js
index a002ffe..953a5e1 100644
--- a/10_fibonacci/solution/fibonacci-solution.js
+++ b/10_fibonacci/solution/fibonacci-solution.js
@@ -1,4 +1,13 @@
-const fibonacci = function(count) {
+const fibonacci = function(countArg) {
+    // 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 (count < 0) return "OOPS";
     if (count == 0) return 0;
 
@@ -14,4 +23,4 @@ const fibonacci = function(count) {
     return firstPrev;
 };
 
-module.exports = fibonacci;
+module.exports = fibonacci;
\ No newline at end of file
diff --git a/10_fibonacci/solution/fibonacci-solution.spec.js b/10_fibonacci/solution/fibonacci-solution.spec.js
index 33023e8..fdb0bad 100644
--- a/10_fibonacci/solution/fibonacci-solution.spec.js
+++ b/10_fibonacci/solution/fibonacci-solution.spec.js
@@ -34,4 +34,4 @@ describe('fibonacci', () => {
   test('DOES accept strings', () => {
     expect(fibonacci("8")).toBe(21);
   });
-});
+});
\ No newline at end of file