diff --git a/chronos/streams/tlsstream.nim b/chronos/streams/tlsstream.nim
index a31e603..8605c38 100644
--- a/chronos/streams/tlsstream.nim
+++ b/chronos/streams/tlsstream.nim
@@ -113,20 +113,6 @@ template newTLSStreamProtocolError[T](message: T): ref Exception =
 proc raiseTLSStreamProtoError*[T](message: T) =
   raise newTLSStreamProtocolError(message)
 
-# proc getStringState*(state: cuint): string =
-#   var n = newSeq[string]()
-#   if (state and SSL_CLOSED) == SSL_CLOSED:
-#     n.add("Closed")
-#   if (state and SSL_SENDREC) == SSL_SENDREC:
-#     n.add("SendRec")
-#   if (state and SSL_RECVREC) == SSL_RECVREC:
-#     n.add("RecvRec")
-#   if (state and SSL_SENDAPP) == SSL_SENDAPP:
-#     n.add("SendApp")
-#   if (state and SSL_RECVAPP) == SSL_RECVAPP:
-#     n.add("RecvApp")
-#   result = "{" & n.join(", ") & "} number (" & $state & ")"
-
 proc tlsWriteLoop(stream: AsyncStreamWriter) {.async.} =
   var wstream = cast[TLSStreamWriter](stream)
   var engine: ptr SslEngineContext
@@ -314,7 +300,7 @@ proc getSignerAlgo(xc: X509Certificate): int =
 
 proc newTLSClientAsyncStream*(rsource: AsyncStreamReader,
                               wsource: AsyncStreamWriter,
-                              serverName: string = "",
+                              serverName: string,
                               bufferSize = SSL_BUFSIZE_BIDI,
                               minVersion = TLSVersion.TLS11,
                               maxVersion = TLSVersion.TLS12,
@@ -374,6 +360,9 @@ proc newTLSClientAsyncStream*(rsource: AsyncStreamReader,
     if err == 0:
       raise newException(TLSStreamError, "Could not initialize TLS layer")
   else:
+    if len(serverName) == 0:
+      raise newException(TLSStreamError, "serverName must not be empty string")
+
     let err = sslClientReset(addr result.ccontext, serverName, 0)
     if err == 0:
       raise newException(TLSStreamError, "Could not initialize TLS layer")
diff --git a/tests/testasyncstream.nim b/tests/testasyncstream.nim
index 038aec1..7b52df5 100644
--- a/tests/testasyncstream.nim
+++ b/tests/testasyncstream.nim
@@ -634,8 +634,8 @@ suite "TLSStream test suite":
     var creader = newAsyncStreamReader(conn)
     var cwriter = newAsyncStreamWriter(conn)
     # We are using self-signed certificate
-    var cstream = newTLSClientAsyncStream(creader, cwriter,
-                                          flags = {NoVerifyHost})
+    let flags = {NoVerifyHost, NoVerifyServerName}
+    var cstream = newTLSClientAsyncStream(creader, cwriter, "", flags = flags)
     let res = await cstream.reader.readLine()
     await cstream.reader.closeWait()
     await cstream.writer.closeWait()