diff --git a/lib/connection.js b/lib/connection.js
index f606de13..44b023cb 100644
--- a/lib/connection.js
+++ b/lib/connection.js
@@ -159,7 +159,7 @@ Connection.prototype.cancel = function(processID, secretKey) {
     .addInt16(5678)
     .addInt32(processID)
     .addInt32(secretKey)
-    .addCString('').flush();
+    .flush();
 
   var length = bodyBuffer.length + 4;