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 3791f75249a..226a35823ee 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
@@ -2,7 +2,10 @@
 "Index data and search on the mixed cluster":
  - do:
      cluster.health:
-        wait_for_status: green
+        # if the primary shard of an index with (number_of_replicas > 0) ends up on the new node, the replica cannot be
+        # allocated to the old node (see NodeVersionAllocationDecider). x-pack automatically creates indices with
+        # replicas, for example monitoring-data-*.
+        wait_for_status: yellow
         wait_for_nodes: 2
         timeout: 25s
 
diff --git a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yaml b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yaml
index f1f90cf9d22..6bd578dd96a 100644
--- a/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yaml
+++ b/qa/rolling-upgrade/src/test/resources/rest-api-spec/test/old_cluster/10_basic.yaml
@@ -6,7 +6,7 @@
         body:
           settings:
             index:
-              number_of_replicas: 0
+              number_of_replicas: 1
 
  - do:
      bulk: