diff --git a/lib/swift/Sources/TFramedTransport.swift b/lib/swift/Sources/TFramedTransport.swift
index 59855eb..9f75b5e 100644
--- a/lib/swift/Sources/TFramedTransport.swift
+++ b/lib/swift/Sources/TFramedTransport.swift
@@ -65,7 +65,9 @@
         throw TTransportError(error: .sizeLimit(limit: maxSize, got: toRead))
     }
 
-    return try transport.readAll(size: toRead)
+    let data = try transport.readAll(size: toRead)
+    remainingBytes -= data.count
+    return data
   }
 
   public func flush() throws {
@@ -73,10 +75,6 @@
     let buff = writeBuffer
     writeBuffer = Data()
 
-    if buff.count - TFramedTransport.headerSize < 0 {
-      throw TTransportError(error: .unknown)
-    }
-
     let frameSize = encodeFrameSize(size: UInt32(buff.count))
 
     try transport.write(data: frameSize)