diff --git a/src/net_processing.cpp b/src/net_processing.cpp
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -4979,10 +4979,16 @@
     }
 
     if (msg_type == NetMsgType::AVAHELLO) {
-        if (!pfrom.m_avalanche_state) {
-            pfrom.m_avalanche_state = std::make_unique<CNode::AvalancheState>();
+        if (pfrom.m_avalanche_state) {
+            LogPrint(
+                BCLog::AVALANCHE,
+                "Ignoring avahello from peer %d: already in our node set\n",
+                pfrom.GetId());
+            return;
         }
 
+        pfrom.m_avalanche_state = std::make_unique<CNode::AvalancheState>();
+
         CHashVerifier<CDataStream> verifier(&vRecv);
         avalanche::Delegation delegation;
         verifier >> delegation;
diff --git a/test/functional/abc_p2p_avalanche_peer_discovery.py b/test/functional/abc_p2p_avalanche_peer_discovery.py
--- a/test/functional/abc_p2p_avalanche_peer_discovery.py
+++ b/test/functional/abc_p2p_avalanche_peer_discovery.py
@@ -250,6 +250,12 @@
 
         self.wait_until(lambda: has_node_count(2))
 
+        self.log.info("Check that repeated avahello messages are ignored")
+        for i in range(3):
+            with node.assert_debug_log(['Ignoring avahello from peer']):
+                peer_proof_known.send_avahello(
+                    interface_delegation_hex, delegated_key)
+
         self.log.info("Invalidate the proof and check the nodes are removed")
         tip = node.getbestblockhash()
         # Invalidate the block with the proof utxo