diff --git a/markitup/jquery.markitup.js b/markitup/jquery.markitup.js
index 5bb69c3..a1371b8 100755
--- a/markitup/jquery.markitup.js
+++ b/markitup/jquery.markitup.js
@@ -512,7 +512,7 @@
 						} else {
 							iFrame.insertBefore(header);
 						}	
-						previewWindow = iFrame[iFrame.length - 1].contentWindow || frame[iFrame.length - 1];
+						previewWindow = iFrame[iFrame.length - 1].contentWindow || iFrame[iFrame.length - 1];
 					}
 				} else if (altKey === true) {
 					if (iFrame) {