diff --git a/package-lock.json b/package-lock.json
index 213677f..2f2a447 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@satyam-seth/otp-field",
-  "version": "1.0.4",
+  "version": "1.0.5",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@satyam-seth/otp-field",
-      "version": "1.0.4",
+      "version": "1.0.5",
       "license": "ISC",
       "devDependencies": {
         "@types/chai": "^4.3.6",
diff --git a/package.json b/package.json
index ef2daea..80740d8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@satyam-seth/otp-field",
-  "version": "1.0.4",
+  "version": "1.0.5",
   "description": "A configurable OTP field built using TypeScript and SCSS",
   "repository": {
     "type": "git",
diff --git a/src/ts/utils/regex.ts b/src/ts/utils/regex.ts
index 05f8599..25199f8 100644
--- a/src/ts/utils/regex.ts
+++ b/src/ts/utils/regex.ts
@@ -30,7 +30,7 @@ export function getOTPRegexForValueType(valueType: OTPValueType): RegExp {
       return /[^a-z0-9]/g; // Match anything except alphanumeric lower characters
 
     case OTPValueType.ALPHANUMERIC_UPPER:
-      return /[^A-Za-z0-9]/g; // Match anything except alphanumeric upper characters
+      return /[^A-Z0-9]/g; // Match anything except alphanumeric upper characters
 
     // throw error for invalid type
     default:
diff --git a/tests/utils/regex.ts b/tests/utils/regex.ts
new file mode 100644
index 0000000..2ba3eb6
--- /dev/null
+++ b/tests/utils/regex.ts
@@ -0,0 +1,46 @@
+import { expect } from 'chai';
+import { describe, it } from 'mocha';
+import { getOTPRegexForValueType, OTPValueType } from '../../src/ts/main';
+
+describe('Test getOTPRegexForValueType function', () => {
+  it('should return valid regex for valid value type', () => {
+    const numericRegex = getOTPRegexForValueType(OTPValueType.NUMERIC);
+    expect(numericRegex.toString()).to.equal('/[^0-9]/g');
+
+    const alphabeticRegex = getOTPRegexForValueType(OTPValueType.ALPHABETIC);
+    expect(alphabeticRegex.toString()).to.equal('/[^A-Za-z]/g');
+
+    const alphabeticLowerRegex = getOTPRegexForValueType(
+      OTPValueType.ALPHABETIC_LOWER
+    );
+    expect(alphabeticLowerRegex.toString()).to.equal('/[^a-z]/g');
+
+    const alphabeticUpperRegex = getOTPRegexForValueType(
+      OTPValueType.ALPHABETIC_UPPER
+    );
+    expect(alphabeticUpperRegex.toString()).to.equal('/[^A-Z]/g');
+
+    const alphanumericRegex = getOTPRegexForValueType(
+      OTPValueType.ALPHANUMERIC
+    );
+    expect(alphanumericRegex.toString()).to.equal('/[^A-Za-z0-9]/g');
+
+    const alphanumericLowerRegex = getOTPRegexForValueType(
+      OTPValueType.ALPHANUMERIC_LOWER
+    );
+    expect(alphanumericLowerRegex.toString()).to.equal('/[^a-z0-9]/g');
+
+    const alphanumericUpperRegex = getOTPRegexForValueType(
+      OTPValueType.ALPHANUMERIC_UPPER
+    );
+    expect(alphanumericUpperRegex.toString()).to.equal('/[^A-Z0-9]/g');
+  });
+
+  it('should throw error for invalid value type', () => {
+    // @ts-ignore
+    expect(() => getOTPRegexForValueType('invalid')).to.throw(
+      Error,
+      'Invalid OTP field value type'
+    );
+  });
+});