diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
index 8aec2758f8..3f9d14c328 100644
--- a/src/node/interfaces.cpp
+++ b/src/node/interfaces.cpp
@@ -431,7 +431,7 @@ public:
 };
 
 // NOLINTNEXTLINE(misc-no-recursion)
-bool FillBlock(const CBlockIndex* index, const FoundBlock& block, UniqueLock<RecursiveMutex>& lock, const CChain& active, const BlockManager& blockman)
+bool FillBlock(const CBlockIndex* index, const FoundBlock& block, UniqueLock<RecursiveMutex>& lock, const CChain& active, const BlockManager& blockman) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
 {
     if (!index) return false;
     if (block.m_hash) *block.m_hash = index->GetBlockHash();