diff --git a/td/mtproto/Transport.cpp b/td/mtproto/Transport.cpp
index 9d90e18a0..9498ea00d 100644
--- a/td/mtproto/Transport.cpp
+++ b/td/mtproto/Transport.cpp
@@ -227,11 +227,7 @@ Status Transport::read_crypto_impl(int X, MutableSlice message, const AuthKey &a
   auto *header = reinterpret_cast<HeaderT *>(message.begin());
   *header_ptr = header;
   auto to_decrypt = MutableSlice(header->encrypt_begin(), message.uend());
-  to_decrypt.truncate(to_decrypt.size() & ~15);
-  if (to_decrypt.size() % 16 != 0) {
-    return Status::Error(PSLICE() << "Invalid mtproto message: size of encrypted part is not multiple of 16 [size = "
-                                  << to_decrypt.size() << "]");
-  }
+  to_decrypt.remove_suffix(to_decrypt.size() & 15);
 
   if (header->auth_key_id != auth_key.id()) {
     return Status::Error(PSLICE() << "Invalid mtproto message: auth_key_id mismatch [found = "