diff --git a/src/components/views/rooms/BasicMessageComposer.js b/src/components/views/rooms/BasicMessageComposer.js
index eabb97a6f5..110df355fe 100644
--- a/src/components/views/rooms/BasicMessageComposer.js
+++ b/src/components/views/rooms/BasicMessageComposer.js
@@ -179,6 +179,7 @@ export default class BasicMessageEditor extends React.Component {
         const {partCreator} = model;
         const text = event.clipboardData.getData("text/plain");
         if (text) {
+            this._modifiedFlag = true;
             const range = getRangeForSelection(this._editorRef, model, document.getSelection());
             const parts = parsePlainTextMessage(text, partCreator);
             replaceRangeAndMoveCaret(range, parts);