diff --git a/rhodecode/api/views/pull_request_api.py b/rhodecode/api/views/pull_request_api.py
--- a/rhodecode/api/views/pull_request_api.py
+++ b/rhodecode/api/views/pull_request_api.py
@@ -659,9 +659,9 @@ def update_pull_request(
     commit_changes = {"added": [], "common": [], "removed": []}
     if str2bool(Optional.extract(update_commits)):
         if PullRequestModel().has_valid_update_type(pull_request):
-            _version, _commit_changes = PullRequestModel().update_commits(
+            update_response = PullRequestModel().update_commits(
                 pull_request)
-            commit_changes = _commit_changes or commit_changes
+            commit_changes = update_response.changes or commit_changes
         Session().commit()
 
     reviewers_changes = {"added": [], "removed": []}
@@ -687,5 +687,5 @@ def update_pull_request(
         'updated_commits': commit_changes,
         'updated_reviewers': reviewers_changes
     }
+
     return data
-
diff --git a/rhodecode/tests/models/test_changeset_status.py b/rhodecode/tests/models/test_changeset_status.py
--- a/rhodecode/tests/models/test_changeset_status.py
+++ b/rhodecode/tests/models/test_changeset_status.py
@@ -80,7 +80,7 @@ def test_pull_request_stays_if_update_wi
         voted_status, *pull_request.reviewers)
 
     # Update, without change
-    version, changes = PullRequestModel().update_commits(pull_request)
+    PullRequestModel().update_commits(pull_request)
 
     # Expect that review status is the voted_status
     expected_review_status = voted_status
@@ -99,7 +99,7 @@ def test_pull_request_under_review_if_up
 
     # Update, with change
     pr_util.update_source_repository()
-    version, changes = PullRequestModel().update_commits(pull_request)
+    PullRequestModel().update_commits(pull_request)
 
     # Expect that review status is the voted_status
     expected_review_status = db.ChangesetStatus.STATUS_UNDER_REVIEW