diff --git a/td/mtproto/HandshakeConnection.h b/td/mtproto/HandshakeConnection.h
index 5c9341dd..fb8d74c7 100644
--- a/td/mtproto/HandshakeConnection.h
+++ b/td/mtproto/HandshakeConnection.h
@@ -73,7 +73,8 @@ class HandshakeConnection
     }
     packet.confirm_read(12);
 
-    TRY_STATUS(handshake_->on_message(packet.as_slice(), this, context_.get()));
+    auto fixed_packet_size = packet.size() & ~3;  // remove some padded data
+    TRY_STATUS(handshake_->on_message(packet.as_slice().truncate(fixed_packet_size), this, context_.get()));
     return Status::OK();
   }
 };
diff --git a/td/mtproto/Transport.cpp b/td/mtproto/Transport.cpp
index 0e65c82e..738938c2 100644
--- a/td/mtproto/Transport.cpp
+++ b/td/mtproto/Transport.cpp
@@ -98,6 +98,7 @@ Status Transport::read_crypto_impl(int X, MutableSlice message, const AuthKey &a
   auto *header = &as<HeaderT>(message.begin());
   *header_ptr = header;
   auto to_decrypt = MutableSlice(header->encrypt_begin(), message.uend());
+  to_decrypt = 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() << "]");
@@ -287,7 +288,7 @@ Result<uint64> Transport::read_auth_key_id(Slice message) {
 Status Transport::read(MutableSlice message, const AuthKey &auth_key, PacketInfo *info, MutableSlice *data,
                        int32 *error_code) {
   if (message.size() < 8) {
-    if (message.size() == 4) {
+    if (message.size() >= 4) {
       *error_code = as<int32>(message.begin());
       return Status::OK();
     }