diff --git a/src/validation.cpp b/src/validation.cpp
index d320a46c60..33a7bcb2f0 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1621,6 +1621,7 @@ static bool TxOutDBEntryIsSame(const CTxOut& block_txout, const CTxOut& txdb_txo
  *  When FAILED is returned, view is left in an indeterminate state. */
 DisconnectResult CChainState::DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view)
 {
+    AssertLockHeld(::cs_main);
     bool fClean = true;
 
     CBlockUndo blockUndo;
diff --git a/src/validation.h b/src/validation.h
index 476b933def..2326cb8dd1 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -719,7 +719,8 @@ public:
     bool AcceptBlock(const std::shared_ptr<const CBlock>& pblock, BlockValidationState& state, CBlockIndex** ppindex, bool fRequested, const FlatFilePos* dbp, bool* fNewBlock) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     // Block (dis)connection on a given view:
-    DisconnectResult DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view);
+    DisconnectResult DisconnectBlock(const CBlock& block, const CBlockIndex* pindex, CCoinsViewCache& view)
+        EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
     bool ConnectBlock(const CBlock& block, BlockValidationState& state, CBlockIndex* pindex,
                       CCoinsViewCache& view, std::set<std::pair<uint256, COutPoint>>* setPeginsSpent, bool fJustCheck = false) EXCLUSIVE_LOCKS_REQUIRED(cs_main);