diff --git a/src/avalanche/processor.h b/src/avalanche/processor.h
--- a/src/avalanche/processor.h
+++ b/src/avalanche/processor.h
@@ -63,11 +63,6 @@
  */
 static constexpr int AVALANCHE_MAX_INFLIGHT_POLL = 10;
 
-/**
- * How many UTXOs can be used for a single proof.
- */
-static constexpr int AVALANCHE_MAX_PROOF_STAKES = 1000;
-
 namespace avalanche {
 
 class Delegation;
diff --git a/src/avalanche/proof.h b/src/avalanche/proof.h
--- a/src/avalanche/proof.h
+++ b/src/avalanche/proof.h
@@ -18,6 +18,11 @@
 
 class CCoinsView;
 
+/**
+ * How many UTXOs can be used for a single proof.
+ */
+static constexpr int AVALANCHE_MAX_PROOF_STAKES = 1000;
+
 namespace avalanche {
 
 class ProofValidationState;
diff --git a/src/avalanche/proof.cpp b/src/avalanche/proof.cpp
--- a/src/avalanche/proof.cpp
+++ b/src/avalanche/proof.cpp
@@ -54,6 +54,10 @@
         return state.Invalid(ProofValidationResult::NO_STAKE);
     }
 
+    if (stakes.size() > AVALANCHE_MAX_PROOF_STAKES) {
+        return state.Invalid(ProofValidationResult::TOO_MANY_UTXOS);
+    }
+
     std::unordered_set<COutPoint, SaltedOutpointHasher> utxos;
     for (const SignedStake &ss : stakes) {
         const Stake &s = ss.getStake();
diff --git a/src/avalanche/validation.h b/src/avalanche/validation.h
--- a/src/avalanche/validation.h
+++ b/src/avalanche/validation.h
@@ -15,6 +15,7 @@
     DUST_THRESOLD,
     DUPLICATE_STAKE,
     INVALID_SIGNATURE,
+    TOO_MANY_UTXOS,
 
     // UTXO based errors.
     MISSING_UTXO,
diff --git a/src/init.cpp b/src/init.cpp
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -2461,6 +2461,11 @@
                         InitError(_("the avalanche proof has invalid stake "
                                     "signatures"));
                         return false;
+                    case avalanche::ProofValidationResult::TOO_MANY_UTXOS:
+                        InitError(strprintf(_("the avalanche proof has too "
+                                              "many utxos (max: %u)"),
+                                            AVALANCHE_MAX_PROOF_STAKES));
+                        return false;
                     default:
                         InitError(_("the avalanche proof is invalid"));
                         return false;
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -3984,12 +3984,6 @@
         verifier >> delegation;
 
         avalanche::Proof proof;
-        // TODO: read proof from message
-        if (proof.getStakes().size() > AVALANCHE_MAX_PROOF_STAKES) {
-            Misbehaving(pfrom, 100, "too-large-avalanche-proof");
-            return;
-        }
-
         avalanche::DelegationState state;
         CPubKey pubkey;
         if (!delegation.verify(state, proof, pubkey)) {
diff --git a/src/rpc/avalanche.cpp b/src/rpc/avalanche.cpp
--- a/src/rpc/avalanche.cpp
+++ b/src/rpc/avalanche.cpp
@@ -86,11 +86,6 @@
         return false;
     }
 
-    if (proof.getStakes().size() > AVALANCHE_MAX_PROOF_STAKES) {
-        throw JSONRPCError(RPC_INVALID_PARAMS,
-                           "Avalanche proof has too many UTXOs");
-    }
-
     return g_avalanche->addNode(nodeid, proof,
                                 avalanche::DelegationBuilder(proof).build());
 }
diff --git a/test/functional/abc_rpc_avalancheproof.py b/test/functional/abc_rpc_avalancheproof.py
--- a/test/functional/abc_rpc_avalancheproof.py
+++ b/test/functional/abc_rpc_avalancheproof.py
@@ -6,13 +6,12 @@
 
 from test_framework.avatools import get_stakes
 from test_framework.key import ECKey
-
 from test_framework.mininode import P2PInterface
-
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.test_node import ErrorMatch
 from test_framework.util import (
+    append_config,
     assert_equal,
-    assert_raises_rpc_error,
 )
 
 AVALANCHE_MAX_PROOF_STAKES = 1000
@@ -83,18 +82,14 @@
             proof_sequence, proof_expiration,
             proof_master, maximum_stakes)
         peerid1 = add_interface_node(node)
-        node.addavalanchenode(
-            peerid1, proof_master, good_proof)
+        assert node.addavalanchenode(peerid1, proof_master, good_proof)
 
         self.log.info("A proof using too many stakes should be rejected...")
-        bad_proof = node.buildavalancheproof(
+        too_many_utxos = node.buildavalancheproof(
             proof_sequence, proof_expiration,
             proof_master, too_many_stakes)
-
         peerid2 = add_interface_node(node)
-        assert_raises_rpc_error(-32602, "Avalanche proof has too many UTXOs",
-                                node.addavalanchenode,
-                                peerid2, proof_master, bad_proof)
+        assert not node.addavalanchenode(peerid2, proof_master, too_many_utxos)
 
         # Test invalid proofs
         self.log.info("Bad proof should be rejected at startup")
@@ -136,6 +131,16 @@
                                "the avalanche proof has duplicated stake")
         check_proof_init_error(bad_sig,
                                "the avalanche proof has invalid stake signatures")
+        # The too many utxos case creates a proof which is that large that it
+        # cannot fit on the command line
+        append_config(node.datadir, ["avaproof={}".format(too_many_utxos)])
+        node.assert_start_raises_init_error(
+            self.extra_args[0] + [
+                "-avamasterkey=cND2ZvtabDbJ1gucx9GWH6XT9kgTAqfb6cotPt5Q5CyxVDhid2EN",
+            ],
+            expected_msg="Error: the avalanche proof has too many utxos",
+            match=ErrorMatch.PARTIAL_REGEX,
+        )
 
 
 if __name__ == '__main__':