diff --git a/src/offset.js b/src/offset.js
index 907dc0989..18e6eebed 100644
--- a/src/offset.js
+++ b/src/offset.js
@@ -144,8 +144,10 @@ jQuery.fn.extend( {
 			}
 
 			// Add offsetParent borders
-			parentOffset.top += jQuery.css( offsetParent[ 0 ], "borderTopWidth", true );
-			parentOffset.left += jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true );
+			parentOffset = {
+				top: parentOffset.top + jQuery.css( offsetParent[ 0 ], "borderTopWidth", true ),
+				left: parentOffset.left + jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true )
+			};
 		}
 
 		// Subtract parent offsets and element margins