diff --git a/src/init.cpp b/src/init.cpp
index 3f68ea1021109..af1d4a0851070 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1631,9 +1631,16 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
 
     // ********************************************************* Step 11: start node
 
+    int chain_active_height;
+
     //// debug print
-    LogPrintf("mapBlockIndex.size() = %u\n",   mapBlockIndex.size());
-    LogPrintf("nBestHeight = %d\n",                   chainActive.Height());
+    {
+        LOCK(cs_main);
+        LogPrintf("mapBlockIndex.size() = %u\n", mapBlockIndex.size());
+        chain_active_height = chainActive.Height();
+    }
+    LogPrintf("nBestHeight = %d\n", chain_active_height);
+
     if (gArgs.GetBoolArg("-listenonion", DEFAULT_LISTEN_ONION))
         StartTorControl(threadGroup, scheduler);
 
@@ -1649,7 +1656,7 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
     connOptions.nMaxOutbound = std::min(MAX_OUTBOUND_CONNECTIONS, connOptions.nMaxConnections);
     connOptions.nMaxAddnode = MAX_ADDNODE_CONNECTIONS;
     connOptions.nMaxFeeler = 1;
-    connOptions.nBestHeight = chainActive.Height();
+    connOptions.nBestHeight = chain_active_height;
     connOptions.uiInterface = &uiInterface;
     connOptions.nSendBufferMaxSize = 1000*gArgs.GetArg("-maxsendbuffer", DEFAULT_MAXSENDBUFFER);
     connOptions.nReceiveFloodSize = 1000*gArgs.GetArg("-maxreceivebuffer", DEFAULT_MAXRECEIVEBUFFER);