diff --git a/monkey/monkey_island/cc/encryptor.py b/monkey/monkey_island/cc/encryptor.py
index 3a3d052f6..84e6fba9d 100644
--- a/monkey/monkey_island/cc/encryptor.py
+++ b/monkey/monkey_island/cc/encryptor.py
@@ -39,7 +39,7 @@ class Encryptor:
     def enc(self, message):
         cipher_iv = Random.new().read(AES.block_size)
         cipher = AES.new(self._cipher_key, AES.MODE_CBC, cipher_iv)
-        return base64.b64encode(cipher_iv + cipher.encrypt(self._pad(message)))
+        return base64.b64encode(cipher_iv + cipher.encrypt(str(self._pad(message))))  # ciper.encrypt expects str
 
     def dec(self, enc_message):
         enc_message = base64.b64decode(enc_message)