diff --git a/index.js b/index.js
index 3169794..923d1b6 100644
--- a/index.js
+++ b/index.js
@@ -165,7 +165,7 @@ function encrypt_aes (text, pass, mode = encryption_mode_cbc_256) {
   const salt = crypto.randomBytes (mode.salt_size);
   // eslint-disable-next-line no-sync
   const key = crypto.pbkdf2Sync (
-    Buffer.from (pass, 'utf-8'),
+    Buffer.from (pass),
     salt,
     mode.iterations,
     mode.key_size,
@@ -203,7 +203,7 @@ function decrypt_aes (
     buf = buf.slice (mode.salt_size);
     // eslint-disable-next-line no-sync
     const key = crypto.pbkdf2Sync (
-      Buffer.from (pass, 'utf-8'),
+      Buffer.from (pass),
       salt,
       mode.iterations,
       mode.key_size,
@@ -216,7 +216,7 @@ function decrypt_aes (
       cipher.update (buf),
       cipher.final ()
     ])
-      .toString ('utf-8');
+      .toString ();
   }
   catch (e) {
     if (rethrow)