Vanilla Javascript... Hopefully pretty easy. I have a Text Area that I use a custom Event Handler in to modify the pasted content. function doPasteThang(e){ e.preventDefault(); //... some code here myTextArea.value = modifedString; } So that all works. However, once something has been pasted, I can no longer use a Browsers CTRL + Z to Undo the last thing entered. I am missing something, and not really sure what I am missing. Like a mutation? new CustomEvent? Can anyone suggest what I am missing?