diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index d43c22e4da3..dbf8da69c15 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -51,7 +51,7 @@ struct CUpdatedBlock
 
 static Mutex cs_blockchange;
 static std::condition_variable cond_blockchange;
-static CUpdatedBlock latestblock;
+static CUpdatedBlock latestblock GUARDED_BY(cs_blockchange);
 
 CTxMemPool& EnsureMemPool()
 {
@@ -208,7 +208,7 @@ static UniValue getbestblockhash(const JSONRPCRequest& request)
 void RPCNotifyBlockChange(bool ibd, const CBlockIndex * pindex)
 {
     if(pindex) {
-        std::lock_guard<std::mutex> lock(cs_blockchange);
+        LOCK(cs_blockchange);
         latestblock.hash = pindex->GetBlockHash();
         latestblock.height = pindex->nHeight;
     }
@@ -243,9 +243,9 @@ static UniValue waitfornewblock(const JSONRPCRequest& request)
         WAIT_LOCK(cs_blockchange, lock);
         block = latestblock;
         if(timeout)
-            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&block]{return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
+            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&block]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
         else
-            cond_blockchange.wait(lock, [&block]{return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
+            cond_blockchange.wait(lock, [&block]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.height != block.height || latestblock.hash != block.hash || !IsRPCRunning(); });
         block = latestblock;
     }
     UniValue ret(UniValue::VOBJ);
@@ -285,9 +285,9 @@ static UniValue waitforblock(const JSONRPCRequest& request)
     {
         WAIT_LOCK(cs_blockchange, lock);
         if(timeout)
-            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&hash]{return latestblock.hash == hash || !IsRPCRunning();});
+            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&hash]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.hash == hash || !IsRPCRunning();});
         else
-            cond_blockchange.wait(lock, [&hash]{return latestblock.hash == hash || !IsRPCRunning(); });
+            cond_blockchange.wait(lock, [&hash]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.hash == hash || !IsRPCRunning(); });
         block = latestblock;
     }
 
@@ -329,9 +329,9 @@ static UniValue waitforblockheight(const JSONRPCRequest& request)
     {
         WAIT_LOCK(cs_blockchange, lock);
         if(timeout)
-            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&height]{return latestblock.height >= height || !IsRPCRunning();});
+            cond_blockchange.wait_for(lock, std::chrono::milliseconds(timeout), [&height]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.height >= height || !IsRPCRunning();});
         else
-            cond_blockchange.wait(lock, [&height]{return latestblock.height >= height || !IsRPCRunning(); });
+            cond_blockchange.wait(lock, [&height]() EXCLUSIVE_LOCKS_REQUIRED(cs_blockchange) {return latestblock.height >= height || !IsRPCRunning(); });
         block = latestblock;
     }
     UniValue ret(UniValue::VOBJ);