diff --git a/package.json b/package.json
index 1add486..4b513f0 100644
--- a/package.json
+++ b/package.json
@@ -60,7 +60,6 @@
 		"@types/node": "^18.11.18",
 		"@types/semver": "^7.3.13",
 		"ava": "^5.1.0",
-		"clear-module": "^4.1.2",
 		"del": "^7.0.0",
 		"del-cli": "^5.0.0",
 		"delay": "^5.0.0",
diff --git a/source/index.ts b/source/index.ts
index a7bb596..c0301a0 100644
--- a/source/index.ts
+++ b/source/index.ts
@@ -357,22 +357,12 @@ export default class Conf<T extends Record<string, any> = Record<string, unknown
 			return data.toString();
 		}
 
+		// Check if an initialization vector has been used to encrypt the data.
 		try {
-			// Check if an initialization vector has been used to encrypt the data
-			if (this.#encryptionKey) {
-				try {
-					if (data.slice(16, 17).toString() === ':') {
-						const initializationVector = data.slice(0, 16);
-						const password = crypto.pbkdf2Sync(this.#encryptionKey, initializationVector.toString(), 10_000, 32, 'sha512');
-						const decipher = crypto.createDecipheriv(encryptionAlgorithm, password, initializationVector);
-						data = Buffer.concat([decipher.update(Buffer.from(data.slice(17))), decipher.final()]).toString('utf8');
-					} else {
-						// TODO: Remove this in the next major version.
-						const decipher = crypto.createDecipher(encryptionAlgorithm, this.#encryptionKey);
-						data = Buffer.concat([decipher.update(Buffer.from(data)), decipher.final()]).toString('utf8');
-					}
-				} catch {}
-			}
+			const initializationVector = data.slice(0, 16);
+			const password = crypto.pbkdf2Sync(this.#encryptionKey, initializationVector.toString(), 10_000, 32, 'sha512');
+			const decipher = crypto.createDecipheriv(encryptionAlgorithm, password, initializationVector);
+			return Buffer.concat([decipher.update(Buffer.from(data.slice(17))), decipher.final()]).toString('utf8');
 		} catch {}
 
 		return data.toString();
diff --git a/test/index.ts b/test/index.ts
index ec2ef1e..22a3a8a 100644
--- a/test/index.ts
+++ b/test/index.ts
@@ -475,17 +475,6 @@ test('encryption - corrupt file', t => {
 	t.is(after.get('foo'), undefined);
 });
 
-test('decryption - migration to initialization vector', t => {
-	// The `test/config-encrypted-with-conf-4-1-0.json` file contains `{"unicorn": "🦄"}` JSON data which is encrypted with conf@4.1.0 and password `abcd1234`
-	const config = new Conf({
-		cwd: 'test',
-		encryptionKey: 'abcd1234',
-		configName: 'config-encrypted-with-conf-4-1-0',
-	});
-
-	t.deepEqual(config.store, {unicorn: '🦄'});
-});
-
 test('onDidChange()', t => {
 	const {config} = t.context;