1 files changed, 3 insertions, 0 deletions
diff --git a/src/versionbits.cpp b/src/versionbits.cpp
index df2ec4e056..07ecc93c93 100644
--- a/src/versionbits.cpp
+++ b/src/versionbits.cpp
@@ -192,6 +192,7 @@ public:
 
 ThresholdState VersionBitsState(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache)
 {
+    LOCK(cache.mutex);
     return VersionBitsConditionChecker(pos).GetStateFor(pindexPrev, params, cache.caches[pos]);
 }
 
@@ -202,6 +203,7 @@ BIP9Stats VersionBitsStatistics(const CBlockIndex* pindexPrev, const Consensus::
 
 int VersionBitsStateSinceHeight(const CBlockIndex* pindexPrev, const Consensus::Params& params, Consensus::DeploymentPos pos, VersionBitsCache& cache)
 {
+    LOCK(cache.mutex);
     return VersionBitsConditionChecker(pos).GetStateSinceHeightFor(pindexPrev, params, cache.caches[pos]);
 }
 
@@ -212,6 +214,7 @@ uint32_t VersionBitsMask(const Consensus::Params& params, Consensus::DeploymentP
 
 void VersionBitsCache::Clear()
 {
+    LOCK(mutex);
     for (unsigned int d = 0; d < Consensus::MAX_VERSION_BITS_DEPLOYMENTS; d++) {
         caches[d].clear();
     }