diff --git a/src/net.h b/src/net.h
--- a/src/net.h
+++ b/src/net.h
@@ -986,6 +986,7 @@
     void Release() { nRefCount--; }
 
     void AddAddressKnown(const CAddress &_addr) {
+        assert(m_addr_known);
         m_addr_known->insert(_addr.GetKey());
     }
 
@@ -993,6 +994,7 @@
         // Known checking here is only to save space from duplicates.
         // SendMessages will filter it again for knowns that were added
         // after addresses were pushed.
+        assert(m_addr_known);
         if (_addr.IsValid() && !m_addr_known->contains(_addr.GetKey())) {
             if (vAddrToSend.size() >= MAX_ADDR_TO_SEND) {
                 vAddrToSend[insecure_rand.randrange(vAddrToSend.size())] =
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -4356,6 +4356,7 @@
             PoissonNextSend(nNow, AVG_ADDRESS_BROADCAST_INTERVAL);
         std::vector<CAddress> vAddr;
         vAddr.reserve(pto->vAddrToSend.size());
+        assert(pto->m_addr_known);
         for (const CAddress &addr : pto->vAddrToSend) {
             if (!pto->m_addr_known->contains(addr.GetKey())) {
                 pto->m_addr_known->insert(addr.GetKey());