diff --git a/src/addrman.h b/src/addrman.h
index 18f306228..f347cba6c 100644
--- a/src/addrman.h
+++ b/src/addrman.h
@@ -455,6 +455,7 @@ public:
 
     void Clear()
     {
+        LOCK(cs);
         std::vector<int>().swap(vRandom);
         nKey = GetRandHash();
         for (size_t bucket = 0; bucket < ADDRMAN_NEW_BUCKET_COUNT; bucket++) {