diff --git a/srcpkgs/libArcus/patches/protobuf.patch b/srcpkgs/libArcus/patches/protobuf.patch
new file mode 100644
index 00000000000..e138558cf2b
--- /dev/null
+++ b/srcpkgs/libArcus/patches/protobuf.patch
@@ -0,0 +1,42 @@
+Migrate away from previously deprecated functions dropped in protobuf>=3.18.0_1.
+
+--- a/src/Socket_p.h
++++ b/src/Socket_p.h
+@@ -128,9 +128,6 @@
+ 
+         static const int keep_alive_rate = 500; //Number of milliseconds between sending keepalive packets
+ 
+-        // This value determines when protobuf should warn about very large messages.
+-        static const int message_size_warning = 400 * 1048576;
+-
+         // This value determines when protobuf should error out because the message is too large.
+         // Due to the way Protobuf is implemented, messages large than 512MiB will cause issues.
+         static const int message_size_maximum = 500 * 1048576;
+@@ -362,11 +359,15 @@
+             return;
+         }
+ 
+-        uint32_t message_size = message->ByteSize();
+-        if(platform_socket.writeUInt32(message_size) == -1)
++        auto message_size = message->ByteSizeLong();
++        if (message_size > UINT32_MAX) {
++            error(ErrorCode::SendFailedError, "Message size is too large to send");
++            return;
++        }
++
++        if(platform_socket.writeUInt32(static_cast<uint32_t>(message_size)) == -1)
+         {
+             error(ErrorCode::SendFailedError, "Could not send message size");
+-            return;
+         }
+ 
+         uint32_t type_id = message_types.getMessageTypeId(message);
+@@ -548,7 +549,7 @@
+ 
+         google::protobuf::io::ArrayInputStream array(wire_message->data, wire_message->size);
+         google::protobuf::io::CodedInputStream stream(&array);
+-        stream.SetTotalBytesLimit(message_size_maximum, message_size_warning);
++        stream.SetTotalBytesLimit(message_size_maximum);
+         if(!message->ParseFromCodedStream(&stream))
+         {
+             error(ErrorCode::ParseFailedError, "Failed to parse message:" + std::string(wire_message->data));