diff --git a/app/javascript/mastodon/containers/status_container.js b/app/javascript/mastodon/containers/status_container.js
index bbc0d5e968..b3555c76e5 100644
--- a/app/javascript/mastodon/containers/status_container.js
+++ b/app/javascript/mastodon/containers/status_container.js
@@ -36,6 +36,8 @@ const messages = defineMessages({
   redraftConfirm: { id: 'confirmations.redraft.confirm', defaultMessage: 'Delete & redraft' },
   redraftMessage: { id: 'confirmations.redraft.message', defaultMessage: 'Are you sure you want to delete this status and re-draft it? Favourites and boosts will be lost, and replies to the original post will be orphaned.' },
   blockConfirm: { id: 'confirmations.block.confirm', defaultMessage: 'Block' },
+  replyConfirm: { id: 'confirmations.reply.confirm', defaultMessage: 'Reply' },
+  replyMessage: { id: 'confirmations.reply.message', defaultMessage: 'Replying now will overwrite the message you are currently composing. Are you sure you want to proceed?' },
 });
 
 const makeMapStateToProps = () => {
@@ -51,7 +53,18 @@ const makeMapStateToProps = () => {
 const mapDispatchToProps = (dispatch, { intl }) => ({
 
   onReply (status, router) {
-    dispatch(replyCompose(status, router));
+    dispatch((_, getState) => {
+      let state = getState();
+      if (state.getIn(['compose', 'text']).trim().length !== 0) {
+        dispatch(openModal('CONFIRM', {
+          message: intl.formatMessage(messages.replyMessage),
+          confirm: intl.formatMessage(messages.replyConfirm),
+          onConfirm: () => dispatch(replyCompose(status, router)),
+        }));
+      } else {
+        dispatch(replyCompose(status, router));
+      }
+    });
   },
 
   onModalReblog (status) {
diff --git a/app/javascript/mastodon/features/status/index.js b/app/javascript/mastodon/features/status/index.js
index 7d1bc2ca48..2cd17b8051 100644
--- a/app/javascript/mastodon/features/status/index.js
+++ b/app/javascript/mastodon/features/status/index.js
@@ -54,6 +54,8 @@ const messages = defineMessages({
   revealAll: { id: 'status.show_more_all', defaultMessage: 'Show more for all' },
   hideAll: { id: 'status.show_less_all', defaultMessage: 'Show less for all' },
   detailedStatus: { id: 'status.detailed_status', defaultMessage: 'Detailed conversation view' },
+  replyConfirm: { id: 'confirmations.reply.confirm', defaultMessage: 'Reply' },
+  replyMessage: { id: 'confirmations.reply.message', defaultMessage: 'Replying now will overwrite the message you are currently composing. Are you sure you want to proceed?' },
 });
 
 const makeMapStateToProps = () => {
@@ -98,6 +100,7 @@ const makeMapStateToProps = () => {
       status,
       ancestorsIds,
       descendantsIds,
+      askReplyConfirmation: state.getIn(['compose', 'text']).trim().length !== 0,
     };
   };
 
@@ -119,6 +122,7 @@ class Status extends ImmutablePureComponent {
     ancestorsIds: ImmutablePropTypes.list,
     descendantsIds: ImmutablePropTypes.list,
     intl: PropTypes.object.isRequired,
+    askReplyConfirmation: PropTypes.bool,
   };
 
   state = {
@@ -157,7 +161,16 @@ class Status extends ImmutablePureComponent {
   }
 
   handleReplyClick = (status) => {
-    this.props.dispatch(replyCompose(status, this.context.router.history));
+    let { askReplyConfirmation, dispatch, intl } = this.props;
+    if (askReplyConfirmation) {
+      dispatch(openModal('CONFIRM', {
+        message: intl.formatMessage(messages.replyMessage),
+        confirm: intl.formatMessage(messages.replyConfirm),
+        onConfirm: () => dispatch(replyCompose(status, this.context.router.history)),
+      }));
+    } else {
+      dispatch(replyCompose(status, this.context.router.history));
+    }
   }
 
   handleModalReblog = (status) => {