diff --git a/src/avalanche/peermanager.h b/src/avalanche/peermanager.h
--- a/src/avalanche/peermanager.h
+++ b/src/avalanche/peermanager.h
@@ -159,6 +159,7 @@
      * exists, then it is created.
      */
     PeerId getPeerId(const Proof &proof);
+    PeerId getPeerId(const Proof &proof, ProofValidationState &state);
 
     /**
      * Remove an existing peer.
@@ -189,7 +190,8 @@
     std::vector<NodeId> getNodeIdsForPeer(PeerId peerId) const;
 
 private:
-    PeerSet::iterator fetchOrCreatePeer(const Proof &proof);
+    PeerSet::iterator fetchOrCreatePeer(const Proof &proof,
+                                        ProofValidationState &state);
     bool addNodeToPeer(const PeerSet::iterator &it);
     bool removeNodeFromPeer(const PeerSet::iterator &it, uint32_t count = 1);
 };
diff --git a/src/avalanche/peermanager.cpp b/src/avalanche/peermanager.cpp
--- a/src/avalanche/peermanager.cpp
+++ b/src/avalanche/peermanager.cpp
@@ -15,7 +15,8 @@
 
 bool PeerManager::addNode(NodeId nodeid, const Proof &proof,
                           const Delegation &delegation) {
-    auto it = fetchOrCreatePeer(proof);
+    ProofValidationState validationState;
+    auto it = fetchOrCreatePeer(proof, validationState);
     if (it == peers.end()) {
         return false;
     }
@@ -181,12 +182,18 @@
 }
 
 PeerId PeerManager::getPeerId(const Proof &proof) {
-    auto it = fetchOrCreatePeer(proof);
+    ProofValidationState state;
+    return getPeerId(proof, state);
+}
+
+PeerId PeerManager::getPeerId(const Proof &proof, ProofValidationState &state) {
+    auto it = fetchOrCreatePeer(proof, state);
     return it == peers.end() ? NO_PEER : it->peerid;
 }
 
 PeerManager::PeerSet::iterator
-PeerManager::fetchOrCreatePeer(const Proof &proof) {
+PeerManager::fetchOrCreatePeer(const Proof &proof,
+                               ProofValidationState &state) {
     {
         // Check if we already know of that peer.
         auto &pview = peers.get<proof_index>();
@@ -201,7 +208,6 @@
         LOCK(cs_main);
         const CCoinsViewCache &coins = ::ChainstateActive().CoinsTip();
 
-        ProofValidationState state;
         if (!proof.verify(state, coins)) {
             return peers.end();
         }
diff --git a/src/avalanche/processor.h b/src/avalanche/processor.h
--- a/src/avalanche/processor.h
+++ b/src/avalanche/processor.h
@@ -261,6 +261,12 @@
     class NotificationsHandler;
     std::unique_ptr<interfaces::Handler> chainNotificationsHandler;
 
+    /**
+     * Flag indicating that the proof must be registered at first new block
+     * after IBD
+     */
+    bool mustRegisterProof = false;
+
 public:
     Processor(interfaces::Chain &chain, CConnman *connmanIn,
               NodePeerManager *nodePeerManagerIn);
diff --git a/src/avalanche/processor.cpp b/src/avalanche/processor.cpp
--- a/src/avalanche/processor.cpp
+++ b/src/avalanche/processor.cpp
@@ -6,6 +6,7 @@
 
 #include <avalanche/delegationbuilder.h>
 #include <avalanche/peermanager.h>
+#include <avalanche/validation.h>
 #include <chain.h>
 #include <key_io.h>         // For DecodeSecret
 #include <net_processing.h> // For ::PeerManager
@@ -149,6 +150,20 @@
 
     void updatedBlockTip() override {
         LOCK(m_processor->cs_peerManager);
+
+        if (m_processor->mustRegisterProof &&
+            !::ChainstateActive().IsInitialBlockDownload()) {
+            ProofValidationState state;
+            m_processor->peerManager->getPeerId(m_processor->peerData->proof,
+                                                state);
+            // If proof validation failed due to missing UTXO, maybe the UTXO
+            // will be in a future block.
+            if (state.IsValid() ||
+                state.GetResult() != ProofValidationResult::MISSING_UTXO) {
+                m_processor->mustRegisterProof = false;
+            }
+        }
+
         m_processor->peerManager->updatedBlockTip();
     }
 };
@@ -174,13 +189,8 @@
                                SER_NETWORK, 0);
             stream >> peerData->proof;
 
-            // Ensure the peer manager knows about it.
-            // FIXME: There is no way to register the proof at this time because
-            // we might not have the proper chainstate at the moment. We need to
-            // find a way to delay the registration of the proof until after IBD
-            // has finished and the chain state is settled.
-            // LOCK(cs_peerManager);
-            // peerManager->getPeerId(peerData->proof);
+            // Schedule proof registration at the first new block after IBD.
+            mustRegisterProof = true;
         }
 
         // Generate the delegation to the session key.
diff --git a/test/functional/abc_p2p_avalanche.py b/test/functional/abc_p2p_avalanche.py
--- a/test/functional/abc_p2p_avalanche.py
+++ b/test/functional/abc_p2p_avalanche.py
@@ -373,15 +373,29 @@
         wait_until(has_parked_new_tip, timeout=15)
         assert_equal(node.getbestblockhash(), fork_tip)
 
-        # Restart the node and rebuild the quorum
+        # Restart the node
+        minchainwork = int(node.getblockchaininfo()["chainwork"], 16) + 1
         self.restart_node(0, self.extra_args[0] + [
             "-avaproof={}".format(proof),
             "-avamasterkey=cND2ZvtabDbJ1gucx9GWH6XT9kgTAqfb6cotPt5Q5CyxVDhid2EN",
+            "-minimumchainwork=0x{:x}".format(minchainwork),
         ])
+        self.log.info(
+            "The proof verification should be delayed until IBD is complete")
+        assert node.getblockchaininfo()["initialblockdownload"] is True
+        # Our proof cannot be verified during IBD, so we should have no peer
+        assert not node.getavalanchepeerinfo()
+        # Mining a few more blocks should cause us to leave IBD
+        node.generate(2)
+        # Our proof is now verified and our node is added as a peer
+        assert node.getblockchaininfo()["initialblockdownload"] is False
+        assert_equal(len(node.getavalanchepeerinfo()), 1)
+
+        # Rebuild the quorum
+        self.log.info("Test the avahello signature")
         quorum = get_quorum()
         poll_node = quorum[0]
 
-        # Check the avahello is consistent
         avahello = poll_node.wait_for_avahello().hello
 
         avakey.set(bytes.fromhex(node.getavalanchekey()))