diff --git a/jquery.mousewheel.js b/jquery.mousewheel.js
index a28a661f4..4c2178c95 100755
--- a/jquery.mousewheel.js
+++ b/jquery.mousewheel.js
@@ -58,7 +58,7 @@
         },
 
         getLineHeight: function(elem) {
-          return parseInt($(elem).offsetParent().css('fontSize'), 10);
+          return parseInt($(elem)['offsetParent' in jQuery.fn ? 'offsetParent' : 'parent']().css('fontSize'), 10);
         },
 
         getPageHeight: function(elem) {