1 files changed, 4 insertions, 1 deletions
diff --git a/src/test/test_bitcoin.cpp b/src/test/test_bitcoin.cpp
index 0d7d52478f..fbe9e217ec 100644
--- a/src/test/test_bitcoin.cpp
+++ b/src/test/test_bitcoin.cpp
@@ -149,7 +149,10 @@ TestChain100Setup::CreateAndProcessBlock(const std::vector<CMutableTransaction>&
         block.vtx.push_back(MakeTransactionRef(tx));
     // IncrementExtraNonce creates a valid coinbase and merkleRoot
     unsigned int extraNonce = 0;
-    IncrementExtraNonce(&block, chainActive.Tip(), extraNonce);
+    {
+        LOCK(cs_main);
+        IncrementExtraNonce(&block, chainActive.Tip(), extraNonce);
+    }
 
     while (!CheckProofOfWork(block.GetHash(), block.nBits, chainparams.GetConsensus())) ++block.nNonce;