diff --git a/lib/child_process.js b/lib/child_process.js
index a8076865cc3..200ed935252 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -51,7 +51,7 @@ exports.execFile = function (file /* args, options, callback */) {
   // Merge optionArg into options
   if (optionArg) {
     var keys = Object.keys(options);
-    for (var i = 0; i < keys.length; i++) {
+    for (var i = 0, len = keys.length; i < len; i++) {
       var k = keys[i];
       if (optionArg[k] !== undefined) options[k] = optionArg[k];
     }
diff --git a/lib/crypto.js b/lib/crypto.js
index dab3b8ad43e..4a0db0ecb05 100644
--- a/lib/crypto.js
+++ b/lib/crypto.js
@@ -3619,13 +3619,13 @@ exports.createCredentials = function(cred) {
   if (cred.ca) {
     c.shouldVerify = true;
     if ( (typeof(cred.ca) == 'object') && cred.ca.length ) {
-      for(var i=0; i<cred.ca.length; i++)
+      for(var i = 0, len = cred.ca.length; i < len; i++)
         c.context.addCACert(cred.ca[i]);
     } else {
       c.context.addCACert(cred.ca);
     }
   } else {
-    for (var i=0; i<RootCaCerts.length; i++) {
+    for (var i = 0, len = RootCaCerts.length; i < len; i++) {
       c.context.addCACert(RootCaCerts[i]);
     }
   }
diff --git a/lib/dns.js b/lib/dns.js
index 2f033bb0a64..50c28984981 100644
--- a/lib/dns.js
+++ b/lib/dns.js
@@ -26,16 +26,10 @@ function updateTimer() {
   timer.stop();
 
   // Were just checking to see if activeWatchers is empty or not
-  for (var socket in activeWatchers) {
-    if (activeWatchers.hasOwnProperty(socket)) {
-      var max = 20000;
-      var timeout = channel.timeout(max);
-
-      timer.start(timeout, 0);
-      // Short circuit the loop on first find.
-      return;
-    }
-  }
+  if (0 === Object.keys(activeWatchers).length) return;
+  var max = 20000;
+  var timeout = channel.timeout(max);
+  timer.start(timeout, 0);
 }
 
 
diff --git a/lib/readline.js b/lib/readline.js
index 3270e12bf50..e7497174957 100644
--- a/lib/readline.js
+++ b/lib/readline.js
@@ -188,7 +188,7 @@ Interface.prototype._tabComplete = function () {
             var item = group[idx];
             self.output.write(item);
             if (col < maxColumns - 1) {
-              for (var s = 0; s < width - item.length; s++) {
+              for (var s = 0, itemLen = item.length; s < width - itemLen; s++) {
                 self.output.write(' ');
               }
             }
@@ -198,8 +198,8 @@ Interface.prototype._tabComplete = function () {
         self.output.write('\r\n');
       }
 
-      var group = [], c, i;
-      for (i = 0; i < completions.length; i++) {
+      var group = [], c;
+      for (var i = 0, compLen = completions.length; i < compLen; i++) {
         c = completions[i];
         if (c === "") {
           handleGroup(group);
@@ -230,7 +230,7 @@ function commonPrefix(strings) {
   var sorted = strings.slice().sort();
   var min = sorted[0];
   var max = sorted[sorted.length - 1];
-  for (var i = 0; i < min.length; i++) {
+  for (var i = 0, len = min.length; i < len; i++) {
     if (min[i] != max[i]) {
       return min.slice(0, i);
     }
@@ -475,7 +475,7 @@ Interface.prototype._ttyWrite = function (b) {
     default:
       var c = b.toString('utf8');
       var lines = c.split(/\r\n|\n|\r/);
-      for (var i = 0; i < lines.length; i++) {
+      for (var i = 0, len = lines.length; i < len; i++) {
         if (i > 0) {
           this._ttyWrite(new Buffer([13]));
         }