diff --git a/lib/mempool/mempool.js b/lib/mempool/mempool.js
index 0a1c4f8f..723b3f69 100644
--- a/lib/mempool/mempool.js
+++ b/lib/mempool/mempool.js
@@ -210,7 +210,7 @@ Mempool.prototype._addBlock = co(function* addBlock(block) {
  */
 
 Mempool.prototype.removeBlock = co(function* removeBlock(block) {
-  var unlock = yield this.lock();
+  var unlock = yield this.locker.lock();
   try {
     return yield this._removeBlock(block);
   } finally {