diff --git a/core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java b/core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java
index e4b72ef3b28..648fcaa859a 100644
--- a/core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java
+++ b/core/src/main/java/org/elasticsearch/search/builder/SearchSourceBuilder.java
@@ -21,7 +21,6 @@ package org.elasticsearch.search.builder;
 
 import com.carrotsearch.hppc.ObjectFloatHashMap;
 import com.carrotsearch.hppc.cursors.ObjectCursor;
-
 import org.elasticsearch.action.support.ToXContentToBytes;
 import org.elasticsearch.common.Nullable;
 import org.elasticsearch.common.ParseField;
@@ -42,7 +41,6 @@ import org.elasticsearch.index.query.QueryParseContext;
 import org.elasticsearch.index.query.QueryShardContext;
 import org.elasticsearch.script.Script;
 import org.elasticsearch.search.aggregations.AggregationBuilder;
-import org.elasticsearch.search.slice.SliceBuilder;
 import org.elasticsearch.search.aggregations.AggregatorFactories;
 import org.elasticsearch.search.aggregations.AggregatorParsers;
 import org.elasticsearch.search.aggregations.PipelineAggregationBuilder;
@@ -51,6 +49,7 @@ import org.elasticsearch.search.highlight.HighlightBuilder;
 import org.elasticsearch.search.internal.SearchContext;
 import org.elasticsearch.search.rescore.RescoreBuilder;
 import org.elasticsearch.search.searchafter.SearchAfterBuilder;
+import org.elasticsearch.search.slice.SliceBuilder;
 import org.elasticsearch.search.sort.ScoreSortBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
 import org.elasticsearch.search.sort.SortBuilders;
@@ -959,7 +958,7 @@ public final class SearchSourceBuilder extends ToXContentToBytes implements Writ
                 } else if (context.getParseFieldMatcher().match(currentFieldName, SIZE_FIELD)) {
                     size = parser.intValue();
                 } else if (context.getParseFieldMatcher().match(currentFieldName, TIMEOUT_FIELD)) {
-                    timeoutInMillis = parser.longValue();
+                    timeoutInMillis = TimeValue.parseTimeValue(parser.text(), null, TIMEOUT_FIELD.getPreferredName()).millis();
                 } else if (context.getParseFieldMatcher().match(currentFieldName, TERMINATE_AFTER_FIELD)) {
                     terminateAfter = parser.intValue();
                 } else if (context.getParseFieldMatcher().match(currentFieldName, MIN_SCORE_FIELD)) {
@@ -1105,7 +1104,7 @@ public final class SearchSourceBuilder extends ToXContentToBytes implements Writ
         }
 
         if (timeoutInMillis != -1) {
-            builder.field(TIMEOUT_FIELD.getPreferredName(), timeoutInMillis);
+            builder.field(TIMEOUT_FIELD.getPreferredName(), TimeValue.timeValueMillis(timeoutInMillis).toString());
         }
 
         if (terminateAfter != SearchContext.DEFAULT_TERMINATE_AFTER) {
diff --git a/core/src/test/java/org/elasticsearch/search/builder/SearchSourceBuilderTests.java b/core/src/test/java/org/elasticsearch/search/builder/SearchSourceBuilderTests.java
index 419b11dac60..575018a3097 100644
--- a/core/src/test/java/org/elasticsearch/search/builder/SearchSourceBuilderTests.java
+++ b/core/src/test/java/org/elasticsearch/search/builder/SearchSourceBuilderTests.java
@@ -19,6 +19,7 @@
 
 package org.elasticsearch.search.builder;
 
+import org.elasticsearch.ElasticsearchParseException;
 import org.elasticsearch.Version;
 import org.elasticsearch.cluster.ClusterState;
 import org.elasticsearch.cluster.metadata.IndexMetaData;
@@ -89,7 +90,9 @@ import java.util.concurrent.TimeUnit;
 
 import static org.elasticsearch.test.ClusterServiceUtils.createClusterService;
 import static org.elasticsearch.test.ClusterServiceUtils.setState;
+import static org.hamcrest.CoreMatchers.containsString;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.hasToString;
 
 public class SearchSourceBuilderTests extends ESTestCase {
     private static Injector injector;
@@ -593,6 +596,27 @@ public class SearchSourceBuilderTests extends ESTestCase {
         }
     }
 
+    public void testTimeoutWithUnits() throws IOException {
+        final String timeout = randomTimeValue();
+        final String query = "{ \"query\": { \"match_all\": {}}, \"timeout\": \"" + timeout + "\"}";
+        try (XContentParser parser = XContentFactory.xContent(query).createParser(query)) {
+            final SearchSourceBuilder builder = SearchSourceBuilder.fromXContent(createParseContext(parser), aggParsers, suggesters);
+            assertThat(builder.timeoutInMillis(), equalTo(TimeValue.parseTimeValue(timeout, null, "timeout").millis()));
+        }
+    }
+
+    public void testTimeoutWithoutUnits() throws IOException {
+        final int timeout = randomIntBetween(1, 1024);
+        final String query = "{ \"query\": { \"match_all\": {}}, \"timeout\": \"" + timeout + "\"}";
+        try (XContentParser parser = XContentFactory.xContent(query).createParser(query)) {
+            final ElasticsearchParseException e =
+                    expectThrows(
+                            ElasticsearchParseException.class,
+                            () -> SearchSourceBuilder.fromXContent(createParseContext(parser), aggParsers, suggesters));
+            assertThat(e, hasToString(containsString("unit is missing or unrecognized")));
+        }
+    }
+
     public void testEmptyPostFilter() throws IOException {
         SearchSourceBuilder builder = new SearchSourceBuilder();
         String query = "{ \"post_filter\": {} }";