diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/10_basic.yaml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/10_basic.yaml
index 86f58366615..b11e85ff4ea 100644
--- a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/10_basic.yaml
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/mixed_cluster/10_basic.yaml
@@ -78,3 +78,7 @@
        index: test_index
        type: test_type
        id: d12
+
+ - do:
+     indices.flush:
+        index: test_index