diff --git a/src/main/java/org/elasticsearch/action/admin/indices/optimize/TransportOptimizeAction.java b/src/main/java/org/elasticsearch/action/admin/indices/optimize/TransportOptimizeAction.java
index 47b45693fb9..c3b575df3bf 100644
--- a/src/main/java/org/elasticsearch/action/admin/indices/optimize/TransportOptimizeAction.java
+++ b/src/main/java/org/elasticsearch/action/admin/indices/optimize/TransportOptimizeAction.java
@@ -50,8 +50,6 @@ public class TransportOptimizeAction extends TransportBroadcastOperationAction<O
 
     private final IndicesService indicesService;
 
-    private final Object optimizeMutex = new Object();
-
     @Inject
     public TransportOptimizeAction(Settings settings, ThreadPool threadPool, ClusterService clusterService,
                                    TransportService transportService, IndicesService indicesService) {
@@ -61,7 +59,7 @@ public class TransportOptimizeAction extends TransportBroadcastOperationAction<O
 
     @Override
     protected String executor() {
-        return ThreadPool.Names.MERGE;
+        return ThreadPool.Names.OPTIMIZE;
     }
 
     @Override
@@ -118,17 +116,15 @@ public class TransportOptimizeAction extends TransportBroadcastOperationAction<O
 
     @Override
     protected ShardOptimizeResponse shardOperation(ShardOptimizeRequest request) throws ElasticSearchException {
-        synchronized (optimizeMutex) {
-            IndexShard indexShard = indicesService.indexServiceSafe(request.index()).shardSafe(request.shardId());
-            indexShard.optimize(new Engine.Optimize()
-                    .waitForMerge(request.waitForMerge())
-                    .maxNumSegments(request.maxNumSegments())
-                    .onlyExpungeDeletes(request.onlyExpungeDeletes())
-                    .flush(request.flush())
-                    .refresh(request.refresh())
-            );
-            return new ShardOptimizeResponse(request.index(), request.shardId());
-        }
+        IndexShard indexShard = indicesService.indexServiceSafe(request.index()).shardSafe(request.shardId());
+        indexShard.optimize(new Engine.Optimize()
+                .waitForMerge(request.waitForMerge())
+                .maxNumSegments(request.maxNumSegments())
+                .onlyExpungeDeletes(request.onlyExpungeDeletes())
+                .flush(request.flush())
+                .refresh(request.refresh())
+        );
+        return new ShardOptimizeResponse(request.index(), request.shardId());
     }
 
     /**
diff --git a/src/main/java/org/elasticsearch/threadpool/ThreadPool.java b/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
index da947f6787d..1cbc01581c4 100644
--- a/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
+++ b/src/main/java/org/elasticsearch/threadpool/ThreadPool.java
@@ -72,6 +72,7 @@ public class ThreadPool extends AbstractComponent {
         public static final String REFRESH = "refresh";
         public static final String WARMER = "warmer";
         public static final String SNAPSHOT = "snapshot";
+        public static final String OPTIMIZE = "optimize";
     }
 
     public static final String THREADPOOL_GROUP = "threadpool.";
@@ -112,6 +113,7 @@ public class ThreadPool extends AbstractComponent {
                 .put(Names.REFRESH, settingsBuilder().put("type", "scaling").put("keep_alive", "5m").put("size", halfProcMaxAt10).build())
                 .put(Names.WARMER, settingsBuilder().put("type", "scaling").put("keep_alive", "5m").put("size", halfProcMaxAt5).build())
                 .put(Names.SNAPSHOT, settingsBuilder().put("type", "scaling").put("keep_alive", "5m").put("size", halfProcMaxAt5).build())
+                .put(Names.OPTIMIZE, settingsBuilder().put("type", "fixed").put("size", 1).build())
                 .build();
 
         Map<String, ExecutorHolder> executors = Maps.newHashMap();