diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index c968e4d1244..bb3c88f627c 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -180,7 +180,7 @@ ChainTestingSetup::~ChainTestingSetup()
     m_node.banman.reset();
     m_node.addrman.reset();
     m_node.args = nullptr;
-    UnloadBlockIndex(m_node.mempool.get(), *m_node.chainman);
+    WITH_LOCK(::cs_main, UnloadBlockIndex(m_node.mempool.get(), *m_node.chainman));
     m_node.mempool.reset();
     m_node.scheduler.reset();
     m_node.chainman->Reset();
diff --git a/src/validation.cpp b/src/validation.cpp
index e20e2fe5236..438e375988b 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -4028,7 +4028,7 @@ void CChainState::UnloadBlockIndex() {
 // block index state
 void UnloadBlockIndex(CTxMemPool* mempool, ChainstateManager& chainman)
 {
-    LOCK(cs_main);
+    AssertLockHeld(::cs_main);
     chainman.Unload();
     pindexBestHeader = nullptr;
     if (mempool) mempool->clear();
diff --git a/src/validation.h b/src/validation.h
index fdfd29d1f88..1972bf75ea9 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -138,7 +138,7 @@ extern CBlockIndex *pindexBestHeader;
 extern const std::vector<std::string> CHECKLEVEL_DOC;
 
 /** Unload database information */
-void UnloadBlockIndex(CTxMemPool* mempool, ChainstateManager& chainman);
+void UnloadBlockIndex(CTxMemPool* mempool, ChainstateManager& chainman) EXCLUSIVE_LOCKS_REQUIRED(::cs_main);
 /** Run instances of script checking worker threads */
 void StartScriptCheckWorkerThreads(int threads_num);
 /** Stop all of the script checking worker threads */