diff --git a/test_runner/fixtures/compare_fixtures.py b/test_runner/fixtures/compare_fixtures.py
index 530e5afaab..fa488c4446 100644
--- a/test_runner/fixtures/compare_fixtures.py
+++ b/test_runner/fixtures/compare_fixtures.py
@@ -115,7 +115,7 @@ class NeonCompare(PgCompare):
         return self._pg_bin
 
     def flush(self):
-        self.pageserver_http.timeline_checkpoint(self.env.initial_tenant, self.timeline)
+        self.pageserver_http_client.timeline_checkpoint(self.env.initial_tenant, self.timeline)
         self.pageserver_http_client.timeline_gc(self.env.initial_tenant, self.timeline, 0)
 
     def compact(self):