diff --git a/lib/incoming.js b/lib/incoming.js
index <HASH>..<HASH> 100644
--- a/lib/incoming.js
+++ b/lib/incoming.js
@@ -5,6 +5,7 @@ const FIN         = 0x80;
 const RSV1        = 0x40;
 const RSV2        = 0x20;
 const RSV3        = 0x10;
+const RSV_ALL     = RSV1 | RSV2 | RSV3;
 const OPCODE      = 0x0f;
 const MASKED      = 0x80;
 const LENGTH      = 0x7f;
@@ -44,7 +45,7 @@ Incoming.prototype._transform = function(chunk, charset, done) {
     // buffer until we have two bytes to parse
     // and to calculated total head byte length
     if (chunk.length >= 2 && this.needsHeadBase) {
-      if (RSV1 & chunk[0] | RSV2 & chunk[0] | RSV3 & chunk[0]) {
+      if (RSV_ALL & chunk[0]) {
         this.emit('error', new Error('RSV flag should not be set.'));
 
         return;
make RSV flag a little bit more efficient

make RSV flag a little bit more efficient