diff --git a/lib/buffer.js b/lib/buffer.js
index 53553253209923..88c0e8226dadfb 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -190,27 +190,21 @@ Buffer.compare = function compare(a, b) {
 
 
 Buffer.isEncoding = function(encoding) {
-  var loweredCase = false;
-  for (;;) {
-    switch (encoding) {
-      case 'hex':
-      case 'utf8':
-      case 'utf-8':
-      case 'ascii':
-      case 'binary':
-      case 'base64':
-      case 'ucs2':
-      case 'ucs-2':
-      case 'utf16le':
-      case 'utf-16le':
-        return true;
-
-      default:
-        if (loweredCase)
-          return false;
-        encoding = ('' + encoding).toLowerCase();
-        loweredCase = true;
-    }
+  var loweredCase = ('' + encoding).toLowerCase();
+  switch (loweredCase) {
+    case 'hex':
+    case 'utf8':
+    case 'utf-8':
+    case 'ascii':
+    case 'binary':
+    case 'base64':
+    case 'ucs2':
+    case 'ucs-2':
+    case 'utf16le':
+    case 'utf-16le':
+      return true;
+    default:
+      return false;
   }
 };