diff --git a/API/Makefile b/API/Makefile
deleted file mode 100644
index ce8acab..0000000
--- a/API/Makefile
+++ /dev/null
@@ -1,12 +0,0 @@
-all: build
-
-build:
-	./generate_wrappers.rb
-
-rebuild: clean build
-
-clean:
-	rm -f out/Types/*
-	rm -f out/Methods/*
-
-.PHONY: all build rebuild clean
diff --git a/Sources/Telegrammer/Bot/Telegram/Bot.swift b/Sources/Telegrammer/Bot/Telegram/Bot.swift
index 62697d9..3e91022 100644
--- a/Sources/Telegrammer/Bot/Telegram/Bot.swift
+++ b/Sources/Telegrammer/Bot/Telegram/Bot.swift
@@ -104,7 +104,7 @@ public final class Bot: BotProtocol {
         }
 
         if let object = object as? MultipartEncodable {
-            return .string(try object.encodeBody(boundary: boundary))
+            return .byteBuffer(try object.encodeBody(boundary: boundary))
         }
 
         return nil
diff --git a/Sources/Telegrammer/Types/TelegramEncodables.swift b/Sources/Telegrammer/Types/TelegramEncodables.swift
index abd8336..650a8c9 100644
--- a/Sources/Telegrammer/Types/TelegramEncodables.swift
+++ b/Sources/Telegrammer/Types/TelegramEncodables.swift
@@ -7,6 +7,7 @@
 
 import Foundation
 import MultipartKit
+import struct NIO.ByteBufferAllocator
 
 /// Represent Telegram type, which will be encoded as Json on sending to server
 protocol JSONEncodable: Encodable {}
@@ -21,7 +22,10 @@ extension JSONEncodable {
 protocol MultipartEncodable: Encodable {}
 
 extension MultipartEncodable {
-    func encodeBody(boundary: String) throws -> String {
-        return try FormDataEncoder().encode(self, boundary: boundary)
+    func encodeBody(boundary: String) throws -> ByteBuffer {
+        let encoder = FormDataEncoder()
+        var buffer = ByteBufferAllocator().buffer(capacity: 0)
+        try encoder.encode(self, boundary: boundary, into: &buffer)
+        return buffer
     }
 }