diff --git a/Maths/CoPrimeCheck.js b/Maths/CoPrimeCheck.js
index 3d9a0a3993..bade446771 100644
--- a/Maths/CoPrimeCheck.js
+++ b/Maths/CoPrimeCheck.js
@@ -28,13 +28,13 @@ const GetEuclidGCD = (arg1, arg2) => {
 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.')
+    throw 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.
     */
-  return GetEuclidGCD(firstNumber, secondNumber) === 1
+  return GetEuclidGCD(Math.abs(firstNumber), Math.abs(secondNumber)) === 1
 }
 
 export { CoPrimeCheck }
diff --git a/Maths/test/CoPrimeCheck.test.js b/Maths/test/CoPrimeCheck.test.js
new file mode 100644
index 0000000000..2276f055d3
--- /dev/null
+++ b/Maths/test/CoPrimeCheck.test.js
@@ -0,0 +1,29 @@
+import { CoPrimeCheck } from '../CoPrimeCheck'
+
+describe('CoPrimeCheck', () => {
+  it.each([
+    [1, 1],
+    [1, 2],
+    [1, 3],
+    [1, 7],
+    [20, 21],
+    [5, 7],
+    [-5, -7]
+  ])('returns true for %j and %i', (inputA, inputB) => {
+    expect(CoPrimeCheck(inputA, inputB)).toBe(true)
+    expect(CoPrimeCheck(inputB, inputA)).toBe(true)
+  })
+
+  it.each([
+    [5, 15],
+    [13 * 17 * 19, 17 * 23 * 29]
+  ])('returns false for %j and %i', (inputA, inputB) => {
+    expect(CoPrimeCheck(inputA, inputB)).toBe(false)
+    expect(CoPrimeCheck(inputB, inputA)).toBe(false)
+  })
+
+  it('should throw when any of the inputs is not a number', () => {
+    expect(() => CoPrimeCheck('1', 2)).toThrowError()
+    expect(() => CoPrimeCheck(1, '2')).toThrowError()
+  })
+})