diff --git a/core/src/main/java/org/elasticsearch/index/query/QueryParseContext.java b/core/src/main/java/org/elasticsearch/index/query/QueryParseContext.java
index 11053b6cdadd6..6dde6ec3b9202 100644
--- a/core/src/main/java/org/elasticsearch/index/query/QueryParseContext.java
+++ b/core/src/main/java/org/elasticsearch/index/query/QueryParseContext.java
@@ -66,6 +66,15 @@ public boolean isDeprecatedSetting(String setting) {
     public QueryBuilder parseTopLevelQueryBuilder() {
         try {
             QueryBuilder queryBuilder = null;
+            XContentParser.Token first = parser.nextToken();
+            if (first == null) {
+                return null;
+            } else if (first != XContentParser.Token.START_OBJECT) {
+                throw new ParsingException(
+                    parser.getTokenLocation(), "Expected [" + XContentParser.Token.START_OBJECT +
+                    "] but found [" + first + "]", parser.getTokenLocation()
+                );
+            }
             for (XContentParser.Token token = parser.nextToken(); token != XContentParser.Token.END_OBJECT; token = parser.nextToken()) {
                 if (token == XContentParser.Token.FIELD_NAME) {
                     String fieldName = parser.currentName();
@@ -110,7 +119,7 @@ public Optional<QueryBuilder> parseInnerQueryBuilder() throws IOException {
         Optional<QueryBuilder> result;
         try {
             @SuppressWarnings("unchecked")
-            Optional<QueryBuilder> resultCast = (Optional<QueryBuilder>) parser.namedObject(Optional.class, queryName, this); 
+            Optional<QueryBuilder> resultCast = (Optional<QueryBuilder>) parser.namedObject(Optional.class, queryName, this);
             result = resultCast;
         } catch (UnknownNamedObjectException e) {
             // Preserve the error message from 5.0 until we have a compellingly better message so we don't break BWC.
diff --git a/core/src/test/java/org/elasticsearch/rest/action/RestActionsTests.java b/core/src/test/java/org/elasticsearch/rest/action/RestActionsTests.java
new file mode 100644
index 0000000000000..401cc79b02092
--- /dev/null
+++ b/core/src/test/java/org/elasticsearch/rest/action/RestActionsTests.java
@@ -0,0 +1,106 @@
+/*
+ * 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.rest.action;
+
+import com.fasterxml.jackson.core.io.JsonEOFException;
+import java.util.Arrays;
+import org.elasticsearch.common.ParsingException;
+import org.elasticsearch.common.settings.Settings;
+import org.elasticsearch.common.xcontent.NamedXContentRegistry;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.common.xcontent.json.JsonXContent;
+import org.elasticsearch.index.query.MatchQueryBuilder;
+import org.elasticsearch.index.query.QueryBuilder;
+import org.elasticsearch.search.SearchModule;
+import org.elasticsearch.test.ESTestCase;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+
+import java.io.IOException;
+
+import static java.util.Collections.emptyList;
+
+public class RestActionsTests extends ESTestCase {
+
+    private static NamedXContentRegistry xContentRegistry;
+
+    @BeforeClass
+    public static void init() {
+        xContentRegistry = new NamedXContentRegistry(new SearchModule(Settings.EMPTY, false, emptyList()).getNamedXContents());
+    }
+
+    @AfterClass
+    public static void cleanup() {
+        xContentRegistry = null;
+    }
+
+    public void testParseTopLevelBuilder() throws IOException {
+        QueryBuilder query = new MatchQueryBuilder("foo", "bar");
+        String requestBody = "{ \"query\" : " + query.toString() + "}";
+        try (XContentParser parser = createParser(JsonXContent.jsonXContent, requestBody)) {
+            QueryBuilder actual = RestActions.getQueryContent(parser);
+            assertEquals(query, actual);
+        }
+    }
+
+    public void testParseTopLevelBuilderEmptyObject() throws IOException {
+        for (String requestBody : Arrays.asList("{}", "")) {
+            try (XContentParser parser = createParser(JsonXContent.jsonXContent, requestBody)) {
+                QueryBuilder query = RestActions.getQueryContent(parser);
+                assertNull(query);
+            }
+        }
+    }
+
+    public void testParseTopLevelBuilderMalformedJson() throws IOException {
+        for (String requestBody : Arrays.asList("\"\"", "\"someString\"", "\"{\"")) {
+            try (XContentParser parser = createParser(JsonXContent.jsonXContent, requestBody)) {
+                ParsingException exception =
+                    expectThrows(ParsingException.class, () -> RestActions.getQueryContent(parser));
+                assertEquals("Expected [START_OBJECT] but found [VALUE_STRING]", exception.getMessage());
+            }
+        }
+    }
+
+    public void testParseTopLevelBuilderIncompleteJson() throws IOException {
+        for (String requestBody : Arrays.asList("{", "{ \"query\" :")) {
+            try (XContentParser parser = createParser(JsonXContent.jsonXContent, requestBody)) {
+                ParsingException exception =
+                    expectThrows(ParsingException.class, () -> RestActions.getQueryContent(parser));
+                assertEquals("Failed to parse", exception.getMessage());
+                assertEquals(JsonEOFException.class, exception.getRootCause().getClass());
+            }
+        }
+    }
+
+    public void testParseTopLevelBuilderUnknownParameter() throws IOException {
+        String requestBody = "{ \"foo\" : \"bar\"}";
+        try (XContentParser parser = createParser(JsonXContent.jsonXContent, requestBody)) {
+            ParsingException exception = expectThrows(ParsingException.class, () -> RestActions.getQueryContent(parser));
+            assertEquals("request does not support [foo]", exception.getMessage());
+        }
+    }
+
+    @Override
+    protected NamedXContentRegistry xContentRegistry() {
+        return xContentRegistry;
+    }
+
+}