diff --git a/reminder_bot.py b/reminder_bot.py
index 696d080..cabd95b 100644
--- a/reminder_bot.py
+++ b/reminder_bot.py
@@ -9,16 +9,16 @@
 from slack_sdk.webhook import WebhookClient
 
 
-def load_key(keyfile):
+def load_key(keyfile: str):
     """
     Loads the key from the current directory named `key.key`
     """
     return open(keyfile, "rb").read()
 
 
-def decrypt(filename, key):
+def decrypt(filename: str, key: bytes):
     """
-    Given a filename (str) and key (bytes), it decrypts the file and write it
+    Given a filename (str) and key (bytes), it decrypts the file
     """
     f = Fernet(key)
     with open(filename, "rb") as file: