diff --git a/core/src/main/java/org/elasticsearch/action/NoopActionListener.java b/core/src/main/java/org/elasticsearch/action/NoopActionListener.java
new file mode 100644
index 00000000000..89c2aecc5f6
--- /dev/null
+++ b/core/src/main/java/org/elasticsearch/action/NoopActionListener.java
@@ -0,0 +1,47 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.action;
+
+/**
+ * An ActionListener that does nothing. Used when we need a listener but don't
+ * care to listen for the result.
+ */
+public final class NoopActionListener<Response> implements ActionListener<Response> {
+    /**
+     * Get the instance of NoopActionListener cast appropriately.
+     */
+    @SuppressWarnings("unchecked") // Safe because we do nothing with the type.
+    public static <Response> ActionListener<Response> instance() {
+        return (ActionListener<Response>) INSTANCE;
+    }
+
+    private static final NoopActionListener<Object> INSTANCE = new NoopActionListener<Object>();
+
+    private NoopActionListener() {
+    }
+
+    @Override
+    public void onResponse(Response response) {
+    }
+
+    @Override
+    public void onFailure(Throwable e) {
+    }
+}
diff --git a/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/AbstractBaseReindexRestHandler.java b/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/AbstractBaseReindexRestHandler.java
new file mode 100644
index 00000000000..ab4fbcc72b1
--- /dev/null
+++ b/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/AbstractBaseReindexRestHandler.java
@@ -0,0 +1,83 @@
+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.elasticsearch.plugin.reindex;
+
+import org.elasticsearch.action.ActionRequest;
+import org.elasticsearch.action.ActionRequestValidationException;
+import org.elasticsearch.action.NoopActionListener;
+import org.elasticsearch.action.support.TransportAction;
+import org.elasticsearch.client.Client;
+import org.elasticsearch.cluster.ClusterService;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.indices.query.IndicesQueriesRegistry;
+import org.elasticsearch.rest.BaseRestHandler;
+import org.elasticsearch.rest.BytesRestResponse;
+import org.elasticsearch.rest.RestChannel;
+import org.elasticsearch.rest.RestController;
+import org.elasticsearch.rest.RestRequest;
+import org.elasticsearch.rest.RestStatus;
+import org.elasticsearch.tasks.Task;
+
+import java.io.IOException;
+
+public abstract class AbstractBaseReindexRestHandler<Request extends ActionRequest<Request>, Response extends BulkIndexByScrollResponse, TA extends TransportAction<Request, Response>>
+        extends BaseRestHandler {
+    protected final IndicesQueriesRegistry indicesQueriesRegistry;
+    private final ClusterService clusterService;
+    private final TA action;
+
+    protected AbstractBaseReindexRestHandler(Settings settings, RestController controller, Client client,
+            IndicesQueriesRegistry indicesQueriesRegistry, ClusterService clusterService, TA action) {
+        super(settings, controller, client);
+        this.indicesQueriesRegistry = indicesQueriesRegistry;
+        this.clusterService = clusterService;
+        this.action = action;
+    }
+
+    protected void execute(RestRequest request, Request internalRequest, RestChannel channel) throws IOException {
+        if (request.paramAsBoolean("wait_for_completion", false)) {
+            action.execute(internalRequest, new BulkIndexByScrollResponseContentListener<Response>(channel));
+            return;
+        }
+        /*
+         * Lets try and validate before forking launching the task so we can
+         * return errors even if we aren't waiting.
+         */
+        ActionRequestValidationException validationException = internalRequest.validate();
+        if (validationException != null) {
+            channel.sendResponse(new BytesRestResponse(channel, validationException));
+            return;
+        }
+        Task task = action.execute(internalRequest, NoopActionListener.instance());
+        sendTask(channel, task);
+    }
+
+    private void sendTask(RestChannel channel, Task task) throws IOException {
+        XContentBuilder builder = channel.newBuilder();
+        builder.startObject();
+        builder.startObject("task");
+        builder.field("node", clusterService.localNode().getId());
+        builder.field("id", task.getId());
+        builder.endObject();
+        builder.endObject();
+        channel.sendResponse(new BytesRestResponse(RestStatus.OK, builder));
+    }
+}
diff --git a/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/RestReindexAction.java b/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/RestReindexAction.java
index 3364f476895..971f38899b6 100644
--- a/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/RestReindexAction.java
+++ b/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/RestReindexAction.java
@@ -19,10 +19,15 @@
 
 package org.elasticsearch.plugin.reindex;
 
+import java.io.IOException;
+import java.util.List;
+import java.util.Map;
+
 import org.elasticsearch.action.WriteConsistencyLevel;
 import org.elasticsearch.action.index.IndexRequest;
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.client.Client;
+import org.elasticsearch.cluster.ClusterService;
 import org.elasticsearch.common.ParseField;
 import org.elasticsearch.common.ParsingException;
 import org.elasticsearch.common.inject.Inject;
@@ -36,26 +41,20 @@ import org.elasticsearch.common.xcontent.XContentParser;
 import org.elasticsearch.index.VersionType;
 import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.indices.query.IndicesQueriesRegistry;
-import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.BytesRestResponse;
 import org.elasticsearch.rest.RestChannel;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
 import org.elasticsearch.script.Script;
 
-import java.io.IOException;
-import java.util.List;
-import java.util.Map;
-
 import static org.elasticsearch.common.unit.TimeValue.parseTimeValue;
-import static org.elasticsearch.plugin.reindex.ReindexAction.INSTANCE;
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 import static org.elasticsearch.rest.RestStatus.BAD_REQUEST;
 
 /**
  * Expose IndexBySearchRequest over rest.
  */
-public class RestReindexAction extends BaseRestHandler {
+public class RestReindexAction extends AbstractBaseReindexRestHandler<ReindexRequest, ReindexResponse, TransportReindexAction> {
     private static final ObjectParser<ReindexRequest, QueryParseContext> PARSER = new ObjectParser<>("reindex");
     static {
         ObjectParser.Parser<SearchRequest, QueryParseContext> sourceParser = (parser, search, context) -> {
@@ -97,13 +96,10 @@ public class RestReindexAction extends BaseRestHandler {
         PARSER.declareString(ReindexRequest::setConflicts, new ParseField("conflicts"));
     }
 
-    private IndicesQueriesRegistry indicesQueriesRegistry;
-
     @Inject
     public RestReindexAction(Settings settings, RestController controller, Client client,
-            IndicesQueriesRegistry indicesQueriesRegistry) {
-        super(settings, controller, client);
-        this.indicesQueriesRegistry = indicesQueriesRegistry;
+            IndicesQueriesRegistry indicesQueriesRegistry, ClusterService clusterService, TransportReindexAction action) {
+        super(settings, controller, client, indicesQueriesRegistry, clusterService, action);
         controller.registerHandler(POST, "/_reindex", this);
     }
 
@@ -125,7 +121,7 @@ public class RestReindexAction extends BaseRestHandler {
         }
         parseCommon(internalRequest, request);
 
-        client.execute(INSTANCE, internalRequest, new BulkIndexByScrollResponseContentListener<>(channel));
+        execute(request, internalRequest, channel);
     }
 
     private void badRequest(RestChannel channel, String message) {
diff --git a/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/RestUpdateByQueryAction.java b/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/RestUpdateByQueryAction.java
index e4e4a0ed0d8..9b4075f5193 100644
--- a/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/RestUpdateByQueryAction.java
+++ b/plugins/reindex/src/main/java/org/elasticsearch/plugin/reindex/RestUpdateByQueryAction.java
@@ -19,8 +19,11 @@
 
 package org.elasticsearch.plugin.reindex;
 
+import java.util.Map;
+
 import org.elasticsearch.action.search.SearchRequest;
 import org.elasticsearch.client.Client;
+import org.elasticsearch.cluster.ClusterService;
 import org.elasticsearch.common.bytes.BytesReference;
 import org.elasticsearch.common.collect.Tuple;
 import org.elasticsearch.common.inject.Inject;
@@ -30,7 +33,6 @@ import org.elasticsearch.common.xcontent.XContentFactory;
 import org.elasticsearch.common.xcontent.XContentHelper;
 import org.elasticsearch.common.xcontent.XContentType;
 import org.elasticsearch.indices.query.IndicesQueriesRegistry;
-import org.elasticsearch.rest.BaseRestHandler;
 import org.elasticsearch.rest.RestChannel;
 import org.elasticsearch.rest.RestController;
 import org.elasticsearch.rest.RestRequest;
@@ -38,21 +40,17 @@ import org.elasticsearch.rest.action.search.RestSearchAction;
 import org.elasticsearch.rest.action.support.RestActions;
 import org.elasticsearch.script.Script;
 
-import java.util.Map;
-
 import static org.elasticsearch.plugin.reindex.AbstractBulkByScrollRequest.SIZE_ALL_MATCHES;
 import static org.elasticsearch.plugin.reindex.RestReindexAction.parseCommon;
-import static org.elasticsearch.plugin.reindex.UpdateByQueryAction.INSTANCE;
 import static org.elasticsearch.rest.RestRequest.Method.POST;
 
-public class RestUpdateByQueryAction extends BaseRestHandler {
-    private IndicesQueriesRegistry indicesQueriesRegistry;
-
+public class RestUpdateByQueryAction extends
+        AbstractBaseReindexRestHandler<UpdateByQueryRequest, BulkIndexByScrollResponse, TransportUpdateByQueryAction> {
     @Inject
     public RestUpdateByQueryAction(Settings settings, RestController controller, Client client,
-            IndicesQueriesRegistry indicesQueriesRegistry) {
-        super(settings, controller, client);
-        this.indicesQueriesRegistry = indicesQueriesRegistry;
+            IndicesQueriesRegistry indicesQueriesRegistry, ClusterService clusterService,
+            TransportUpdateByQueryAction action) {
+        super(settings, controller, client, indicesQueriesRegistry, clusterService, action);
         controller.registerHandler(POST, "/{index}/_update_by_query", this);
         controller.registerHandler(POST, "/{index}/{type}/_update_by_query", this);
     }
@@ -108,6 +106,6 @@ public class RestUpdateByQueryAction extends BaseRestHandler {
         internalRequest.setSize(internalRequest.getSource().source().size());
         internalRequest.getSource().source().size(request.paramAsInt("scroll_size", scrollSize));
 
-        client.execute(INSTANCE, internalRequest, new BulkIndexByScrollResponseContentListener<>(channel));
+        execute(request, internalRequest, channel);
     }
 }
diff --git a/plugins/reindex/src/test/java/org/elasticsearch/plugin/reindex/AsyncBulkByScrollActionTest.java b/plugins/reindex/src/test/java/org/elasticsearch/plugin/reindex/AsyncBulkByScrollActionTest.java
index 3c032599237..f69be1c6635 100644
--- a/plugins/reindex/src/test/java/org/elasticsearch/plugin/reindex/AsyncBulkByScrollActionTest.java
+++ b/plugins/reindex/src/test/java/org/elasticsearch/plugin/reindex/AsyncBulkByScrollActionTest.java
@@ -174,8 +174,8 @@ public class AsyncBulkByScrollActionTest extends ESTestCase {
         }
 
         @Override
-        @SuppressWarnings({ "rawtypes", "unchecked" }) // Declaration is raw
-        protected <Request extends ActionRequest, Response extends ActionResponse, RequestBuilder extends ActionRequestBuilder<Request, Response, RequestBuilder>> void doExecute(
+        @SuppressWarnings("unchecked")
+        protected <Request extends ActionRequest<Request>, Response extends ActionResponse, RequestBuilder extends ActionRequestBuilder<Request, Response, RequestBuilder>> void doExecute(
                 Action<Request, Response, RequestBuilder> action, Request request, ActionListener<Response> listener) {
             if (request instanceof ClearScrollRequest) {
                 ClearScrollRequest clearScroll = (ClearScrollRequest) request;
diff --git a/plugins/reindex/src/test/java/org/elasticsearch/plugin/reindex/ReindexRestIT.java b/plugins/reindex/src/test/java/org/elasticsearch/plugin/reindex/ReindexRestIT.java
index d7db03f22dc..a001c32ab36 100644
--- a/plugins/reindex/src/test/java/org/elasticsearch/plugin/reindex/ReindexRestIT.java
+++ b/plugins/reindex/src/test/java/org/elasticsearch/plugin/reindex/ReindexRestIT.java
@@ -22,20 +22,13 @@ package org.elasticsearch.plugin.reindex;
 import com.carrotsearch.randomizedtesting.annotations.Name;
 import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
 
-import org.elasticsearch.plugins.Plugin;
 import org.elasticsearch.test.rest.ESRestTestCase;
 import org.elasticsearch.test.rest.RestTestCandidate;
 import org.elasticsearch.test.rest.parser.RestTestParseException;
 
 import java.io.IOException;
-import java.util.Collection;
 
 public class ReindexRestIT extends ESRestTestCase {
-    @Override
-    protected Collection<Class<? extends Plugin>> nodePlugins() {
-        return pluginList(ReindexPlugin.class);
-    }
-
     public ReindexRestIT(@Name("yaml") RestTestCandidate testCandidate) {
         super(testCandidate);
     }
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/api/reindex.json b/plugins/reindex/src/test/resources/rest-api-spec/api/reindex.json
index 534adad007b..f09efef7c91 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/api/reindex.json
+++ b/plugins/reindex/src/test/resources/rest-api-spec/api/reindex.json
@@ -20,6 +20,11 @@
           "type" : "enum",
           "options" : ["one", "quorum", "all"],
           "description" : "Explicit write consistency setting for the operation"
+        },
+        "wait_for_completion": {
+           "type" : "boolean",
+           "default": false,
+           "description" : "Should the request should block until the reindex is complete."
         }
       }
     },
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/api/update-by-query.json b/plugins/reindex/src/test/resources/rest-api-spec/api/update-by-query.json
index 08e166410ca..0eaa20463e1 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/api/update-by-query.json
+++ b/plugins/reindex/src/test/resources/rest-api-spec/api/update-by-query.json
@@ -185,6 +185,11 @@
           "type": "integer",
           "defaut_value": 100,
           "description": "Size on the scroll request powering the update-by-query"
+        },
+        "wait_for_completion": {
+           "type" : "boolean",
+           "default": false,
+           "description" : "Should the request should block until the reindex is complete."
         }
       }
     },
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/10_basic.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/10_basic.yaml
index f3f80586264..86e48ee945a 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/10_basic.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/10_basic.yaml
@@ -11,6 +11,7 @@
 
   - do:
       reindex:
+        wait_for_completion: true
         body:
           source:
             index: source
@@ -42,6 +43,7 @@
 
   - do:
       reindex:
+        wait_for_completion: true
         body:
           source:
             index:   source
@@ -54,6 +56,34 @@
   - match: {failures: []}
   - is_true: took
 
+---
+"wait_for_completion=true":
+  - do:
+      index:
+        index:   source
+        type:    foo
+        id:      1
+        body:    { "text": "test" }
+  - do:
+      indices.refresh: {}
+
+  - do:
+      reindex:
+        body:
+          source:
+            index: source
+          dest:
+            index: dest
+  - is_true: task.node
+  - is_true: task.id
+  - is_false: updated
+  - is_false: version_conflicts
+  - is_false: batches
+  - is_false: failures
+  - is_false: noops
+  - is_false: took
+  - is_false: created
+
 ---
 "Response format for version conflict":
   - do:
@@ -74,6 +104,7 @@
   - do:
       catch: conflict
       reindex:
+        wait_for_completion: true
         body:
           source:
             index:   source
@@ -113,6 +144,7 @@
 
   - do:
       reindex:
+        wait_for_completion: true
         body:
           conflicts: proceed
           source:
@@ -140,6 +172,7 @@
 
   - do:
       reindex:
+        wait_for_completion: true
         refresh: true
         body:
           source:
@@ -172,6 +205,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -204,6 +238,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -238,6 +273,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -272,6 +308,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: [twitter, blog]
@@ -319,6 +356,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           size: 1
           source:
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/30_search.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/30_search.yaml
index 0cfb1355008..b441342f2da 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/30_search.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/30_search.yaml
@@ -18,6 +18,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: test
@@ -52,6 +53,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           size: 1
           source:
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/40_versioning.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/40_versioning.yaml
index 7a06ea082aa..fdada709095 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/40_versioning.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/40_versioning.yaml
@@ -30,6 +30,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: src
@@ -75,6 +76,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           conflicts: proceed
           source:
@@ -122,6 +124,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index:        src
@@ -166,6 +169,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index:        src
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/50_routing.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/50_routing.yaml
index 9a6b7245c4f..06550b51c78 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/50_routing.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/50_routing.yaml
@@ -12,6 +12,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index:   src
@@ -42,6 +43,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index:   src
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/60_consistency.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/60_consistency.yaml
index 323e51b1149..b60b7e957ad 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/60_consistency.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/reindex/60_consistency.yaml
@@ -23,6 +23,7 @@
       catch: unavailable
       reindex:
         timeout: 1s
+        wait_for_completion: true
         body:
           source:
             index: src
@@ -34,6 +35,7 @@
   - do:
       reindex:
         consistency: one
+        wait_for_completion: true
         body:
           source:
             index: src
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/10_basic.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/10_basic.yaml
index fbf153638b9..13808dfdd2e 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/10_basic.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/10_basic.yaml
@@ -12,6 +12,7 @@
   - do:
       update-by-query:
         index: test
+        wait_for_completion: true
   - match: {updated: 1}
   - match: {version_conflicts: 0}
   - match: {batches: 1}
@@ -20,6 +21,30 @@
   - is_true: took
   - is_false: created # This shouldn't be included in the response
 
+---
+"wait_for_completion=false":
+  - do:
+      index:
+        index:   test
+        type:    foo
+        id:      1
+        body:    { "text": "test" }
+  - do:
+      indices.refresh: {}
+
+  - do:
+      update-by-query:
+        index: test
+  - is_true: task.node
+  - is_true: task.id
+  - is_false: updated
+  - is_false: version_conflicts
+  - is_false: batches
+  - is_false: failures
+  - is_false: noops
+  - is_false: took
+  - is_false: created
+
 ---
 "Response for version conflict":
   - do:
@@ -47,6 +72,7 @@
       catch: conflict
       update-by-query:
         index: test
+        wait_for_completion: true
   - match: {updated: 0}
   - match: {version_conflicts: 1}
   - match: {batches: 1}
@@ -87,6 +113,7 @@
       update-by-query:
         index: test
         conflicts: proceed
+        wait_for_completion: true
   - match: {updated: 0}
   - match: {version_conflicts: 1}
   - match: {batches: 1}
@@ -114,6 +141,7 @@
   - do:
       update-by-query:
         index: twitter
+        wait_for_completion: true
         body:
           query:
             match:
@@ -144,6 +172,7 @@
   - do:
       update-by-query:
         index: twitter
+        wait_for_completion: true
         size: 1
   - match: {updated: 1}
   - match: {version_conflicts: 0}
@@ -184,4 +213,5 @@
       update-by-query:
         index: test
         scroll_size: 1
+        wait_for_completion: true
   - match: {batches: 3}
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/30_new_fields.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/30_new_fields.yaml
index 269450b3dba..f47f3417061 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/30_new_fields.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/30_new_fields.yaml
@@ -45,6 +45,7 @@
   - do:
       update-by-query:
         index: test
+        wait_for_completion: true
   - do:
       indices.refresh: {}
 
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/40_versioning.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/40_versioning.yaml
index 24cbef1a25c..7bbe627d261 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/40_versioning.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/40_versioning.yaml
@@ -12,6 +12,7 @@
   - do:
       update-by-query:
         index: test
+        wait_for_completion: true
   - match: {updated: 1}
   - match: {version_conflicts: 0}
 
diff --git a/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/50_consistency.yaml b/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/50_consistency.yaml
index dc8e3dcb33e..fa29206633a 100644
--- a/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/50_consistency.yaml
+++ b/plugins/reindex/src/test/resources/rest-api-spec/test/update-by-query/50_consistency.yaml
@@ -24,6 +24,7 @@
       update-by-query:
         index: test
         timeout: 1s
+        wait_for_completion: true
   - match:
       failures.0.cause.reason: /Not.enough.active.copies.to.meet.write.consistency.of.\[QUORUM\].\(have.1,.needed.4\)..Timeout\:.\[1s\],.request:.\[BulkShardRequest.to.\[test\].containing.\[1\].requests\]/
 
@@ -31,6 +32,7 @@
       update-by-query:
         index: test
         consistency: one
+        wait_for_completion: true
   - match: {failures: []}
   - match: {updated: 1}
   - match: {version_conflicts: 0}
diff --git a/qa/smoke-test-reindex-with-groovy/src/test/resources/rest-api-spec/test/reindex/10_script.yaml b/qa/smoke-test-reindex-with-groovy/src/test/resources/rest-api-spec/test/reindex/10_script.yaml
index d37a94deea7..903a4efde78 100644
--- a/qa/smoke-test-reindex-with-groovy/src/test/resources/rest-api-spec/test/reindex/10_script.yaml
+++ b/qa/smoke-test-reindex-with-groovy/src/test/resources/rest-api-spec/test/reindex/10_script.yaml
@@ -12,6 +12,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -51,6 +52,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -110,6 +112,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -153,6 +156,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -211,6 +215,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -256,6 +261,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -303,6 +309,7 @@
 
   - do:
       reindex:
+        wait_for_completion: true
         body:
           source:
             index: twitter
@@ -336,6 +343,7 @@
 
   - do:
       reindex:
+        wait_for_completion: true
         refresh: true
         body:
           source:
@@ -377,6 +385,7 @@
   - do:
       reindex:
         refresh: true
+        wait_for_completion: true
         body:
           source:
             index: twitter
diff --git a/qa/smoke-test-reindex-with-groovy/src/test/resources/rest-api-spec/test/update-by-query/10_script.yaml b/qa/smoke-test-reindex-with-groovy/src/test/resources/rest-api-spec/test/update-by-query/10_script.yaml
index a5a8554615a..96ecdf9ffa8 100644
--- a/qa/smoke-test-reindex-with-groovy/src/test/resources/rest-api-spec/test/update-by-query/10_script.yaml
+++ b/qa/smoke-test-reindex-with-groovy/src/test/resources/rest-api-spec/test/update-by-query/10_script.yaml
@@ -13,6 +13,7 @@
       update-by-query:
         index:   twitter
         refresh: true
+        wait_for_completion: true
         body:
           script:
             inline: ctx._source.user = "not" + ctx._source.user
@@ -49,6 +50,7 @@
       update-by-query:
         refresh: true
         index:   twitter
+        wait_for_completion: true
         body:
           script:
             inline: if (ctx._source.user == "kimchy") {ctx._source.user = "not" + ctx._source.user} else {ctx.op = "noop"}
@@ -94,6 +96,7 @@
       update-by-query:
         refresh: true
         index:   twitter
+        wait_for_completion: true
         body:
           script:
             inline: ctx.op = "noop"
@@ -116,6 +119,7 @@
       catch: /Invalid fields added to ctx \[junk\]/
       update-by-query:
         index: twitter
+        wait_for_completion: true
         body:
           script:
             inline: ctx.junk = "stuff"
@@ -135,6 +139,7 @@
       catch: /Modifying \[_id\] not allowed/
       update-by-query:
         index: twitter
+        wait_for_completion: true
         body:
           script:
             inline: ctx._id = "stuff"