diff --git a/Maths/CoPrimeCheck.js b/Maths/CoPrimeCheck.js
index 1bc3d32ce..f85cf8906 100644
--- a/Maths/CoPrimeCheck.js
+++ b/Maths/CoPrimeCheck.js
@@ -20,6 +20,10 @@ const GetEuclidGCD = require('./GetEuclidGCD')
  * @returns return correspond boolean value, if both number are co-prime return `true`, else return `false`.
  */
 const CoPrimeCheck = (firstNumber, secondNumber) => {
+    // firstly, check that input is a number or not.
+    if (typeof firstNumber !== 'number' || typeof secondNumber !== 'number') {
+        return new TypeError('Argument is not a number.');
+    }
   /*
     This is the most efficient algorithm for checking co-primes
     if the GCD of both the numbers is 1 that means they are co-primes.