diff --git a/envelope.py b/envelope.py
index 7ad3a33..e4330a3 100644
--- a/envelope.py
+++ b/envelope.py
@@ -73,7 +73,7 @@ def check(msg, GNUPG_DIRECTORY, beta=False):
         # Looking for signed content
         for part in msg.walk():
             payload = part.get_payload()
-            if part.get_content_type() == "application/pgp-signature" or part.get_content_type() == "application/octet-stream" or (
+            if part.get_content_type() == "application/pgp-signature" or (
                     payload is not None and not part.is_multipart() and part.get_payload(decode=True).find(b"-----BEGIN PGP SIGNATURE-----") >= 0
             ):
                 if part.get_content_type() != "application/pgp-signature":