diff --git a/types/crypto-js/index.d.ts b/types/crypto-js/index.d.ts
index 02db36ab6c..faeeac78e6 100644
--- a/types/crypto-js/index.d.ts
+++ b/types/crypto-js/index.d.ts
@@ -29,7 +29,7 @@ declare namespace CryptoJS {
 	interface StreamCipher extends Cipher {}
 
 	interface CipherHelper {
-		encrypt(message: string, secretPassphrase: string | WordArray, option?: CipherOption): WordArray;
+		encrypt(message: string | LibWordArray, secretPassphrase: string | WordArray, option?: CipherOption): WordArray;
 		decrypt(encryptedMessage: string | WordArray, secretPassphrase: string | WordArray, option?: CipherOption): DecryptedMessage;
 	}
 	interface Encryptor {