diff --git a/String/CheckPascalCase.js b/String/CheckPascalCase.js
index 3af6d9276..4e557b946 100644
--- a/String/CheckPascalCase.js
+++ b/String/CheckPascalCase.js
@@ -10,7 +10,7 @@
 const CheckPascalCase = (VarName) => {
   // firstly, check that input is a string or not.
   if (typeof VarName !== 'string') {
-    return 'Not string(s)'
+    return new TypeError("Argument is not a string.")
   }
 
   const pat = /^[A-Z][A-Za-z]*$/