diff --git a/src/avalanche/processor.cpp b/src/avalanche/processor.cpp
--- a/src/avalanche/processor.cpp
+++ b/src/avalanche/processor.cpp
@@ -216,10 +216,15 @@
 
         peerData = std::make_unique<PeerData>();
         {
-            // The proof.
-            CDataStream stream(ParseHex(argsman.GetArg("-avaproof", "")),
-                               SER_NETWORK, 0);
-            stream >> peerData->proof;
+            try {
+                CDataStream stream(ParseHex(argsman.GetArg("-avaproof", "")),
+                                   SER_NETWORK, 0);
+                stream >> peerData->proof;
+            } catch (const std::exception &e) {
+                LogPrintf("%s\n", e.what());
+                error = _("the supplied avalanche proof has invalid format");
+                return nullptr;
+            }
         }
 
         ProofValidationState proof_state;
@@ -249,6 +254,11 @@
             }
         }
 
+        if (masterKey.GetPubKey() != peerData->proof.getMaster()) {
+            error = _("the master key does not match the proof public key");
+            return nullptr;
+        }
+
         // Generate the delegation to the session key.
         DelegationBuilder dgb(peerData->proof);
         if (sessionKey.GetPubKey() != peerData->proof.getMaster()) {
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
@@ -226,6 +226,14 @@
             expected_msg="Error: the avalanche master key is invalid",
         )
 
+        node.assert_start_raises_init_error(
+            self.extra_args[0] + [
+                "-avaproof={}".format(proof),
+                "-avamasterkey=cN55daf1HotwBAgAKWVgDcoppmUNDtQSfb7XLutTLeAgVc3u8hik",
+            ],
+            expected_msg="Error: the master key does not match the proof public key",
+        )
+
         def check_proof_init_error(proof, message):
             node.assert_start_raises_init_error(
                 self.extra_args[0] + [
@@ -235,6 +243,8 @@
                 expected_msg="Error: " + message,
             )
 
+        check_proof_init_error("This is not a serialized proof",
+                               "the supplied avalanche proof has invalid format")
         check_proof_init_error(no_stake,
                                "the avalanche proof has no stake")
         check_proof_init_error(dust,