diff --git a/core/src/main/java/org/elasticsearch/action/admin/cluster/node/info/NodesInfoResponse.java b/core/src/main/java/org/elasticsearch/action/admin/cluster/node/info/NodesInfoResponse.java
index 05cf60703d9..32f3d8a2769 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/cluster/node/info/NodesInfoResponse.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/cluster/node/info/NodesInfoResponse.java
@@ -32,7 +32,6 @@ import org.elasticsearch.common.xcontent.XContentFactory;
 
 import java.io.IOException;
 import java.util.Map;
-import java.util.stream.Collectors;
 
 /**
  *
@@ -86,8 +85,11 @@ public class NodesInfoResponse extends BaseNodesResponse<NodeInfo> implements To
                 }
             }
 
-            builder.array("roles", nodeInfo.getNode().getRoles().stream().map(DiscoveryNode.Role::getRoleName)
-                    .collect(Collectors.toList()).toArray());
+            builder.startArray("roles");
+            for (DiscoveryNode.Role role : nodeInfo.getNode().getRoles()) {
+                builder.value(role.getRoleName());
+            }
+            builder.endArray();
 
             if (!nodeInfo.getNode().attributes().isEmpty()) {
                 builder.startObject("attributes");
diff --git a/core/src/main/java/org/elasticsearch/action/admin/cluster/node/stats/NodeStats.java b/core/src/main/java/org/elasticsearch/action/admin/cluster/node/stats/NodeStats.java
index 54e96a67c53..3424a88d3b6 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/cluster/node/stats/NodeStats.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/cluster/node/stats/NodeStats.java
@@ -41,7 +41,6 @@ import org.elasticsearch.threadpool.ThreadPoolStats;
 import org.elasticsearch.transport.TransportStats;
 
 import java.io.IOException;
-import java.util.stream.Collectors;
 
 /**
  * Node statistics (dynamic, changes depending on when created).
@@ -305,8 +304,11 @@ public class NodeStats extends BaseNodeResponse implements ToXContent {
             builder.field("host", getNode().getHostName(), XContentBuilder.FieldCaseConversion.NONE);
             builder.field("ip", getNode().getAddress(), XContentBuilder.FieldCaseConversion.NONE);
 
-            builder.array("roles", getNode().getRoles().stream().map(DiscoveryNode.Role::getRoleName)
-                    .collect(Collectors.toList()).toArray());
+            builder.startArray("roles");
+            for (DiscoveryNode.Role role : getNode().getRoles()) {
+                builder.value(role.getRoleName());
+            }
+            builder.endArray();
 
             if (!getNode().attributes().isEmpty()) {
                 builder.startObject("attributes");
diff --git a/core/src/main/java/org/elasticsearch/action/admin/cluster/node/tasks/list/ListTasksResponse.java b/core/src/main/java/org/elasticsearch/action/admin/cluster/node/tasks/list/ListTasksResponse.java
index 2a36a6fe6d0..fcf23971d12 100644
--- a/core/src/main/java/org/elasticsearch/action/admin/cluster/node/tasks/list/ListTasksResponse.java
+++ b/core/src/main/java/org/elasticsearch/action/admin/cluster/node/tasks/list/ListTasksResponse.java
@@ -20,7 +20,6 @@
 package org.elasticsearch.action.admin.cluster.node.tasks.list;
 
 import com.carrotsearch.hppc.cursors.ObjectObjectCursor;
-
 import org.elasticsearch.action.FailedNodeException;
 import org.elasticsearch.action.TaskOperationFailure;
 import org.elasticsearch.action.support.tasks.BaseTasksResponse;
@@ -39,7 +38,6 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.stream.Collectors;
 
 /**
  * Returns the list of tasks currently running on the nodes
@@ -132,8 +130,11 @@ public class ListTasksResponse extends BaseTasksResponse implements ToXContent {
             builder.field("host", node.getHostName());
             builder.field("ip", node.getAddress());
 
-            builder.array("roles", node.getRoles().stream().map(DiscoveryNode.Role::getRoleName)
-                    .collect(Collectors.toList()).toArray());
+            builder.startArray("roles");
+            for (DiscoveryNode.Role role : node.getRoles()) {
+                builder.value(role.getRoleName());
+            }
+            builder.endArray();
 
             if (!node.attributes().isEmpty()) {
                 builder.startObject("attributes");