diff --git a/src/dynafed.cpp b/src/dynafed.cpp
index 29a20294837..e4564c84b1f 100644
--- a/src/dynafed.cpp
+++ b/src/dynafed.cpp
@@ -11,6 +11,7 @@ bool NextBlockIsParameterTransition(const CBlockIndex* pindexPrev, const Consens
         winning_entry.SetNull();
         return false;
     }
+    LOCK(cs_main);
     std::map<uint256, uint32_t> vote_tally;
     assert(next_height >= consensus.dynamic_epoch_length);
     for (int32_t height = next_height - 1; height >= (int32_t)(next_height - consensus.dynamic_epoch_length); --height) {
@@ -62,6 +63,7 @@ DynaFedParamEntry ComputeNextBlockFullCurrentParameters(const CBlockIndex* pinde
     // may be pre-dynafed params
     const CBlockIndex* p_epoch_start = pindexPrev->GetAncestor(epoch_start_height);
     assert(p_epoch_start);
+    LOCK(cs_main);
     ForceUntrimHeader(p_epoch_start);
     if (p_epoch_start->dynafed_params().IsNull()) {
         // We need to construct the "full" current parameters of pre-dynafed
@@ -96,6 +98,7 @@ DynaFedParamEntry ComputeNextBlockCurrentParameters(const CBlockIndex* pindexPre
 {
     assert(pindexPrev);
 
+    LOCK(cs_main);
     ForceUntrimHeader(pindexPrev);
     DynaFedParamEntry entry = ComputeNextBlockFullCurrentParameters(pindexPrev, consensus);
 
diff --git a/src/pegins.cpp b/src/pegins.cpp
index da47025d438..9146d2da509 100644
--- a/src/pegins.cpp
+++ b/src/pegins.cpp
@@ -475,6 +475,7 @@ std::vector<std::pair<CScript, CScript>> GetValidFedpegScripts(const CBlockIndex
         fedpegscripts.push_back(std::make_pair(next_param.m_fedpeg_program, next_param.m_fedpegscript));
     }
 
+    LOCK(cs_main);
     // Next we walk backwards up to M epoch starts
     for (int32_t i = 0; i < (int32_t) params.total_valid_epochs; i++) {
         // We are within total_valid_epochs of the genesis
diff --git a/src/validation.cpp b/src/validation.cpp
index 749c0f98a5c..21508ab7b8f 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -2510,6 +2510,7 @@ void CChainState::UpdateTip(const CBlockIndex* pindexNew)
       this->CoinsTip().DynamicMemoryUsage() * (1.0 / (1<<20)), this->CoinsTip().GetCacheSize(),
       !warning_messages.empty() ? strprintf(" warning='%s'", warning_messages.original) : "");
 
+    LOCK(cs_main);
     ForceUntrimHeader(pindexNew);
     // Do some logging if dynafed parameters changed.
     if (pindexNew->pprev && !pindexNew->dynafed_params().IsNull()) {