diff --git a/src/core.js b/src/core.js
index 4115c5eae..7a854e7f4 100644
--- a/src/core.js
+++ b/src/core.js
@@ -10,8 +10,9 @@ var
 	core_strundefined = typeof undefined,
 
 	// Use the correct document accordingly with window argument (sandbox)
-	document = window.document,
 	location = window.location,
+	document = window.document,
+	docElem = document.documentElement,
 
 	// Map over jQuery in case of overwrite
 	_jQuery = window.jQuery,
diff --git a/src/offset.js b/src/offset.js
index 4efb962ff..e6fd3574c 100644
--- a/src/offset.js
+++ b/src/offset.js
@@ -123,11 +123,11 @@ jQuery.fn.extend({
 
 	offsetParent: function() {
 		return this.map(function() {
-			var offsetParent = this.offsetParent || document.documentElement;
+			var offsetParent = this.offsetParent || docElem;
 			while ( offsetParent && ( !jQuery.nodeName( offsetParent, "html" ) && jQuery.css( offsetParent, "position") === "static" ) ) {
 				offsetParent = offsetParent.offsetParent;
 			}
-			return offsetParent || document.documentElement;
+			return offsetParent || docElem;
 		});
 	}
 });