diff --git a/polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts b/polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts
index 418cd0e..1f2983a 100644
--- a/polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts
+++ b/polygerrit-ui/app/elements/shared/gr-comment/gr-comment.ts
@@ -675,7 +675,13 @@
 
   @observe('comment.message')
   _commentMessageChanged(message: string) {
-    this._messageText = message || '';
+    /*
+     * Only overwrite the message text user has typed if there is no existing
+     * text typed by the user. This prevents the bug where creating another
+     * comment triggered a recomputation of comments and the text written by
+     * the user was lost.
+     */
+    if (!this._messageText) this._messageText = message || '';
   }
 
   _messageTextChanged(_: string, oldValue: string) {
diff --git a/polygerrit-ui/app/elements/shared/gr-comment/gr-comment_test.ts b/polygerrit-ui/app/elements/shared/gr-comment/gr-comment_test.ts
index 31a1614..b963d4b 100644
--- a/polygerrit-ui/app/elements/shared/gr-comment/gr-comment_test.ts
+++ b/polygerrit-ui/app/elements/shared/gr-comment/gr-comment_test.ts
@@ -217,6 +217,29 @@
       assert.isTrue(storageStub.called);
     });
 
+    test('comment message sets messageText only when empty', () => {
+      element.changeNum = 1 as NumericChangeId;
+      element.patchNum = 1 as PatchSetNum;
+      element._messageText = '';
+      element.comment = {
+        author: {
+          name: 'Mr. Peanutbutter',
+          email: 'tenn1sballchaser@aol.com' as EmailAddress,
+        },
+        line: 5,
+        path: 'test',
+        __editing: true,
+        __draft: true,
+        message: 'hello world',
+      };
+      // messageText was empty so overwrite the message now
+      assert.equal(element._messageText, 'hello world');
+
+      element.comment!.message = 'new message';
+      // messageText was already set so do not overwrite it
+      assert.equal(element._messageText, 'hello world');
+    });
+
     test('_getPatchNum', () => {
       element.side = 'PARENT';
       element.patchNum = 1 as PatchSetNum;