diff --git a/lib/connection.js b/lib/connection.js
index 6d9f11f..140cbf3 100644
--- a/lib/connection.js
+++ b/lib/connection.js
@@ -96,6 +96,7 @@ p.password = function(password) {
 };
 
 p._send = function(code, more) {
+  if(!this.stream.writable) return false;
   if(more === true) {
     this.writer.addHeader(code);
   } else {