diff --git a/src/Elm/Kernel/JsArray.js b/src/Elm/Kernel/JsArray.js
index deeafc32..8a45beec 100644
--- a/src/Elm/Kernel/JsArray.js
+++ b/src/Elm/Kernel/JsArray.js
@@ -21,7 +21,7 @@ var _JsArray_initialize = F3(function(size, offset, func)
 {
     var result = new Array(size);
 
-    for (var i = 0; i < size; i++)
+    for (var i = 0; size - i; i++)
     {
         result[i] = func(offset + i);
     }
@@ -33,7 +33,7 @@ var _JsArray_initializeFromList = F2(function (max, ls)
 {
     var result = new Array(max);
 
-    for (var i = 0; i < max && ls.b; i++)
+    for (var i = 0; max - i && ls.b; i++)
     {
         result[i] = ls.a;
         ls = ls.b;
@@ -53,7 +53,7 @@ var _JsArray_unsafeSet = F3(function(index, value, array)
     var length = array.length;
     var result = new Array(length);
 
-    for (var i = 0; i < length; i++)
+    for (var i = 0; length - i; i++)
     {
         result[i] = array[i];
     }
@@ -67,7 +67,7 @@ var _JsArray_push = F2(function(value, array)
     var length = array.length;
     var result = new Array(length + 1);
 
-    for (var i = 0; i < length; i++)
+    for (var i = 0; length - i; i++)
     {
         result[i] = array[i];
     }
@@ -80,7 +80,7 @@ var _JsArray_foldl = F3(function(func, acc, array)
 {
     var length = array.length;
 
-    for (var i = 0; i < length; i++)
+    for (var i = 0; length - i; i++)
     {
         acc = A2(func, array[i], acc);
     }
@@ -90,7 +90,7 @@ var _JsArray_foldl = F3(function(func, acc, array)
 
 var _JsArray_foldr = F3(function(func, acc, array)
 {
-    for (var i = array.length - 1; i >= 0; i--)
+    for (var i = array.length; i--;)
     {
         acc = A2(func, array[i], acc);
     }
@@ -103,7 +103,7 @@ var _JsArray_map = F2(function(func, array)
     var length = array.length;
     var result = new Array(length);
 
-    for (var i = 0; i < length; i++)
+    for (var i = 0; length - i; i++)
     {
         result[i] = func(array[i]);
     }
@@ -116,7 +116,7 @@ var _JsArray_indexedMap = F3(function(func, offset, array)
     var length = array.length;
     var result = new Array(length);
 
-    for (var i = 0; i < length; i++)
+    for (var i = 0; length - i; i++)
     {
         result[i] = A2(func, offset + i, array[i]);
     }
@@ -142,12 +142,12 @@ var _JsArray_appendN = F3(function(n, dest, source)
     var size = destLen + itemsToCopy;
     var result = new Array(size);
 
-    for (var i = 0; i < destLen; i++)
+    for (var i = 0; destLen - i; i++)
     {
         result[i] = dest[i];
     }
 
-    for (var i = 0; i < itemsToCopy; i++)
+    for (var i = 0; itemsToCopy - i; i++)
     {
         result[i + destLen] = source[i];
     }
diff --git a/src/Elm/Kernel/String.js b/src/Elm/Kernel/String.js
index 44b668bb..5cb29a42 100644
--- a/src/Elm/Kernel/String.js
+++ b/src/Elm/Kernel/String.js
@@ -39,7 +39,7 @@ var _String_map = F2(function(func, string)
 	var len = string.length;
 	var array = new Array(len);
 	var i = 0;
-	while (i < len)
+	while (len-i)
 	{
 		var word = string.charCodeAt(i);
 		if (0xD800 <= word && word <= 0xDBFF)
@@ -59,7 +59,7 @@ var _String_filter = F2(function(isGood, str)
 	var arr = [];
 	var len = str.length;
 	var i = 0;
-	while (i < len)
+	while (len-i)
 	{
 		var char = str[i];
 		var word = str.charCodeAt(i);
@@ -83,7 +83,7 @@ function _String_reverse(str)
 	var len = str.length;
 	var arr = new Array(len);
 	var i = 0;
-	while (i < len)
+	while (len-i)
 	{
 		var word = str.charCodeAt(i);
 		if (0xD800 <= word && word <= 0xDBFF)
@@ -106,7 +106,7 @@ var _String_foldl = F3(function(func, state, string)
 {
 	var len = string.length;
 	var i = 0;
-	while (i < len)
+	while (len-i)
 	{
 		var char = string[i];
 		var word = string.charCodeAt(i);
@@ -280,8 +280,9 @@ function _String_toInt(str)
 	var total = 0;
 	var code0 = str.charCodeAt(0);
 	var start = code0 == 0x2B /* + */ || code0 == 0x2D /* - */ ? 1 : 0;
+	var len = str.length;
 
-	for (var i = start; i < str.length; ++i)
+	for (var i = start; len - i; ++i)
 	{
 		var code = str.charCodeAt(i);
 		if (code < 0x30 || 0x39 < code)