diff --git a/polygerrit-ui/app/elements/diff/gr-diff-comment-thread/gr-diff-comment-thread.js b/polygerrit-ui/app/elements/diff/gr-diff-comment-thread/gr-diff-comment-thread.js
index 179758fd2a..392267c79d 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-comment-thread/gr-diff-comment-thread.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-comment-thread/gr-diff-comment-thread.js
@@ -156,18 +156,21 @@
     },
 
     /**
-     * Sets the initial state of the comment thread to have the last
-     * {UNRESOLVED_EXPAND_COUNT} comments expanded by default if the
-     * thread is unresolved.
+     * Sets the initial state of the comment thread.
+     * Expands the thread if one of the following is true:
+     * - last {UNRESOLVED_EXPAND_COUNT} comments expanded by default if the
+     * thread is unresolved,
+     * - it's a robot comment.
      */
     _setInitialExpandedState() {
-      let comment;
       if (this._orderedComments) {
         for (let i = 0; i < this._orderedComments.length; i++) {
-          comment = this._orderedComments[i];
-          comment.collapsed =
-              this._orderedComments.length - i - 1 >= UNRESOLVED_EXPAND_COUNT ||
-              !this._unresolved;
+          const comment = this._orderedComments[i];
+          const isRobotComment = !!comment.robot_id;
+          // False if it's an unresolved comment under UNRESOLVED_EXPAND_COUNT.
+          const resolvedThread = !this._unresolved ||
+                this._orderedComments.length - i - 1 >= UNRESOLVED_EXPAND_COUNT;
+          comment.collapsed = !isRobotComment && resolvedThread;
         }
       }
     },
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-comment-thread/gr-diff-comment-thread_test.html b/polygerrit-ui/app/elements/diff/gr-diff-comment-thread/gr-diff-comment-thread_test.html
index 5a5fc0694d..e1ab0a0a1e 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-comment-thread/gr-diff-comment-thread_test.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff-comment-thread/gr-diff-comment-thread_test.html
@@ -510,6 +510,13 @@ limitations under the License.
         for (let i = 0; i < element.comments.length; i++) {
           assert.isTrue(element.comments[i].collapsed);
         }
+        for (let i = 0; i < element.comments.length; i++) {
+          element.comments[i].robot_id = 123;
+        }
+        element._setInitialExpandedState();
+        for (let i = 0; i < element.comments.length; i++) {
+          assert.isFalse(element.comments[i].collapsed);
+        }
       });
     });