diff --git a/core/src/test/java/org/elasticsearch/action/admin/indices/create/CreateIndexIT.java b/core/src/test/java/org/elasticsearch/action/admin/indices/create/CreateIndexIT.java
index f5333d1288efa..8fbb489d9c263 100644
--- a/core/src/test/java/org/elasticsearch/action/admin/indices/create/CreateIndexIT.java
+++ b/core/src/test/java/org/elasticsearch/action/admin/indices/create/CreateIndexIT.java
@@ -304,6 +304,10 @@ public void testCreateShrinkIndexToN() {
         assertTrue("at least 2 nodes but was: " + dataNodes.size(), dataNodes.size() >= 2);
         DiscoveryNode[] discoveryNodes = dataNodes.values().toArray(DiscoveryNode.class);
         String mergeNode = discoveryNodes[0].getName();
+        // ensure all shards are allocated otherwise the ensure green below might not succeed since we require the merge node
+        // if we change the setting too quickly we will end up with one replica unassigned which can't be assigned anymore due
+        // to the require._name below.
+        ensureGreen();
         // relocate all shards to one node such that we can merge it.
         client().admin().indices().prepareUpdateSettings("source")
             .setSettings(Settings.builder()