diff --git a/core/src/main/java/org/elasticsearch/action/support/ThreadedActionListener.java b/core/src/main/java/org/elasticsearch/action/support/ThreadedActionListener.java
index 2a2bdd7a061..6ed52e1ac46 100644
--- a/core/src/main/java/org/elasticsearch/action/support/ThreadedActionListener.java
+++ b/core/src/main/java/org/elasticsearch/action/support/ThreadedActionListener.java
@@ -50,7 +50,7 @@ public final class ThreadedActionListener<Response> implements ActionListener<Re
             this.threadPool = threadPool;
              // Should the action listener be threaded or not by default. Action listeners are automatically threaded for client
              // nodes and transport client in order to make sure client side code is not executed on IO threads.
-            this.threadedListener = DiscoveryNode.clientNode(settings) || TransportClient.CLIENT_TYPE.equals(settings.get(Client.CLIENT_TYPE_SETTING));
+            this.threadedListener = DiscoveryNode.clientNode(settings) || TransportClient.CLIENT_TYPE.equals(Client.CLIENT_TYPE_SETTING_S.get(settings));
         }
 
         public <Response> ActionListener<Response> wrap(ActionListener<Response> listener) {
diff --git a/core/src/main/java/org/elasticsearch/client/Client.java b/core/src/main/java/org/elasticsearch/client/Client.java
index e7461dabfe1..7795929b1c1 100644
--- a/core/src/main/java/org/elasticsearch/client/Client.java
+++ b/core/src/main/java/org/elasticsearch/client/Client.java
@@ -83,8 +83,11 @@ import org.elasticsearch.action.update.UpdateResponse;
 import org.elasticsearch.client.support.Headers;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.lease.Releasable;
+import org.elasticsearch.common.settings.Setting;
 import org.elasticsearch.common.settings.Settings;
 
+import java.util.function.Function;
+
 /**
  * A client provides a one stop interface for performing actions/operations against the cluster.
  * <p>
@@ -100,7 +103,15 @@ import org.elasticsearch.common.settings.Settings;
  */
 public interface Client extends ElasticsearchClient, Releasable {
 
-    String CLIENT_TYPE_SETTING = "client.type";
+    Setting<String> CLIENT_TYPE_SETTING_S = new Setting<>("client.type", "node", (s) -> {
+        switch (s) {
+            case "node":
+            case "transport":
+                return s;
+            default:
+                throw new IllegalArgumentException("Can't parse [client.type] must be one of [node, transport]");
+        }
+    }, false, Setting.Scope.CLUSTER);
 
     /**
      * The admin client that can be used to perform administrative operations.
diff --git a/core/src/main/java/org/elasticsearch/client/transport/TransportClient.java b/core/src/main/java/org/elasticsearch/client/transport/TransportClient.java
index ea809a8cc38..e6735840736 100644
--- a/core/src/main/java/org/elasticsearch/client/transport/TransportClient.java
+++ b/core/src/main/java/org/elasticsearch/client/transport/TransportClient.java
@@ -115,7 +115,7 @@ public class TransportClient extends AbstractClient {
                 .put( InternalSettingsPreparer.prepareSettings(settings))
                 .put("network.server", false)
                 .put(Node.NODE_CLIENT_SETTING.getKey(), true)
-                .put(CLIENT_TYPE_SETTING, CLIENT_TYPE);
+                .put(CLIENT_TYPE_SETTING_S.getKey(), CLIENT_TYPE);
             return new PluginsService(settingsBuilder.build(), null, null, pluginClasses);
         }
 
diff --git a/core/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java b/core/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java
index 7306ae6ce95..0d9362929ce 100644
--- a/core/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java
+++ b/core/src/main/java/org/elasticsearch/common/settings/ClusterSettings.java
@@ -22,6 +22,7 @@ import org.elasticsearch.action.admin.indices.close.TransportCloseIndexAction;
 import org.elasticsearch.action.support.AutoCreateIndex;
 import org.elasticsearch.action.support.DestructiveOperations;
 import org.elasticsearch.action.support.master.TransportMasterNodeReadAction;
+import org.elasticsearch.client.Client;
 import org.elasticsearch.client.transport.TransportClientNodesService;
 import org.elasticsearch.cluster.ClusterModule;
 import org.elasticsearch.cluster.ClusterName;
@@ -270,6 +271,7 @@ public final class ClusterSettings extends AbstractScopedSettings {
         AutoCreateIndex.AUTO_CREATE_INDEX_SETTING,
         BaseRestHandler.MULTI_ALLOW_EXPLICIT_INDEX,
         ClusterName.CLUSTER_NAME_SETTING,
+        Client.CLIENT_TYPE_SETTING_S,
         InternalSettingsPreparer.IGNORE_SYSTEM_PROPERTIES_SETTING,
         ClusterModule.SHARDS_ALLOCATOR_TYPE_SETTING,
         EsExecutors.PROCESSORS_SETTING)));
diff --git a/core/src/main/java/org/elasticsearch/node/Node.java b/core/src/main/java/org/elasticsearch/node/Node.java
index ea9d0be1eec..2678636ea24 100644
--- a/core/src/main/java/org/elasticsearch/node/Node.java
+++ b/core/src/main/java/org/elasticsearch/node/Node.java
@@ -149,7 +149,7 @@ public class Node implements Releasable {
 
     protected Node(Environment tmpEnv, Version version, Collection<Class<? extends Plugin>> classpathPlugins) {
         Settings tmpSettings = settingsBuilder().put(tmpEnv.settings())
-            .put(Client.CLIENT_TYPE_SETTING, CLIENT_TYPE).build();
+            .put(Client.CLIENT_TYPE_SETTING_S.getKey(), CLIENT_TYPE).build();
         tmpSettings = TribeService.processSettings(tmpSettings);
 
         ESLogger logger = Loggers.getLogger(Node.class, tmpSettings.get("name"));
diff --git a/core/src/test/java/org/elasticsearch/action/ListenerActionIT.java b/core/src/test/java/org/elasticsearch/action/ListenerActionIT.java
index f68cb76c955..a9bb96a0a9f 100644
--- a/core/src/test/java/org/elasticsearch/action/ListenerActionIT.java
+++ b/core/src/test/java/org/elasticsearch/action/ListenerActionIT.java
@@ -61,7 +61,7 @@ public class ListenerActionIT extends ESIntegTestCase {
 
         latch.await();
 
-        boolean shouldBeThreaded = DiscoveryNode.clientNode(client.settings()) || TransportClient.CLIENT_TYPE.equals(client.settings().get(Client.CLIENT_TYPE_SETTING));
+        boolean shouldBeThreaded = DiscoveryNode.clientNode(client.settings()) || TransportClient.CLIENT_TYPE.equals(Client.CLIENT_TYPE_SETTING_S.get(client.settings()));
         if (shouldBeThreaded) {
             assertTrue(threadName.get().contains("listener"));
         } else {
diff --git a/core/src/test/java/org/elasticsearch/client/node/NodeClientIT.java b/core/src/test/java/org/elasticsearch/client/node/NodeClientIT.java
index 966553b8f3d..ae839e8837e 100644
--- a/core/src/test/java/org/elasticsearch/client/node/NodeClientIT.java
+++ b/core/src/test/java/org/elasticsearch/client/node/NodeClientIT.java
@@ -34,12 +34,12 @@ import static org.hamcrest.Matchers.is;
 public class NodeClientIT extends ESIntegTestCase {
     @Override
     protected Settings nodeSettings(int nodeOrdinal) {
-        return settingsBuilder().put(super.nodeSettings(nodeOrdinal)).put(Client.CLIENT_TYPE_SETTING, "anything").build();
+        return settingsBuilder().put(super.nodeSettings(nodeOrdinal)).put(Client.CLIENT_TYPE_SETTING_S.getKey(), "anything").build();
     }
 
     public void testThatClientTypeSettingCannotBeChanged() {
         for (Settings settings : internalCluster().getInstances(Settings.class)) {
-            assertThat(settings.get(Client.CLIENT_TYPE_SETTING), is("node"));
+            assertThat(Client.CLIENT_TYPE_SETTING_S.get(settings), is("node"));
         }
     }
 }
diff --git a/core/src/test/java/org/elasticsearch/client/transport/TransportClientIT.java b/core/src/test/java/org/elasticsearch/client/transport/TransportClientIT.java
index 673dbca80ac..a561b5bcf7b 100644
--- a/core/src/test/java/org/elasticsearch/client/transport/TransportClientIT.java
+++ b/core/src/test/java/org/elasticsearch/client/transport/TransportClientIT.java
@@ -86,17 +86,16 @@ public class TransportClientIT extends ESIntegTestCase {
     public void testThatTransportClientSettingIsSet() {
         TransportClient client = (TransportClient)  internalCluster().client();
         Settings settings = client.injector.getInstance(Settings.class);
-        assertThat(settings.get(Client.CLIENT_TYPE_SETTING), is("transport"));
+        assertThat(Client.CLIENT_TYPE_SETTING_S.get(settings), is("transport"));
     }
 
     public void testThatTransportClientSettingCannotBeChanged() {
         Settings baseSettings = settingsBuilder()
-            .put(Client.CLIENT_TYPE_SETTING, "anything")
             .put(Environment.PATH_HOME_SETTING.getKey(), createTempDir())
              .build();
         try (TransportClient client = TransportClient.builder().settings(baseSettings).build()) {
             Settings settings = client.injector.getInstance(Settings.class);
-            assertThat(settings.get(Client.CLIENT_TYPE_SETTING), is("transport"));
+            assertThat(Client.CLIENT_TYPE_SETTING_S.get(settings), is("transport"));
         }
     }
 }