diff --git a/src/selector.js b/src/selector.js
index fb332465d..64222c3f6 100644
--- a/src/selector.js
+++ b/src/selector.js
@@ -551,7 +551,7 @@ var Expr = Sizzle.selectors = {
 			} else if ( name === "not" ) {
 				var not = match[3];
 
-				for ( i = 0, l = not.length; i < l; i++ ) {
+				for ( var i = 0, l = not.length; i < l; i++ ) {
 					if ( not[i] === elem ) {
 						return false;
 					}