1 files changed, 2 insertions, 1 deletions
diff --git a/src/test/policyestimator_tests.cpp b/src/test/policyestimator_tests.cpp
index 8d288ec993..26a0b495d9 100644
--- a/src/test/policyestimator_tests.cpp
+++ b/src/test/policyestimator_tests.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2011-2017 The Bitcoin Core developers
+// Copyright (c) 2011-2018 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -18,6 +18,7 @@ BOOST_AUTO_TEST_CASE(BlockPolicyEstimates)
 {
     CBlockPolicyEstimator feeEst;
     CTxMemPool mpool(&feeEst);
+    LOCK(mpool.cs);
     TestMemPoolEntryHelper entry;
     CAmount basefee(2000);
     CAmount deltaFee(100);