diff --git a/src/avalanche/processor.cpp b/src/avalanche/processor.cpp
--- a/src/avalanche/processor.cpp
+++ b/src/avalanche/processor.cpp
@@ -215,11 +215,10 @@
         }
 
         peerData = std::make_unique<PeerData>();
-        {
-            // The proof.
-            CDataStream stream(ParseHex(argsman.GetArg("-avaproof", "")),
-                               SER_NETWORK, 0);
-            stream >> peerData->proof;
+        if (!Proof::FromHex(peerData->proof, argsman.GetArg("-avaproof", ""),
+                            error)) {
+            // error is set by FromHex
+            return nullptr;
         }
 
         ProofValidationState proof_state;
diff --git a/src/rpc/avalanche.cpp b/src/rpc/avalanche.cpp
--- a/src/rpc/avalanche.cpp
+++ b/src/rpc/avalanche.cpp
@@ -80,10 +80,11 @@
     const NodeId nodeid = request.params[0].get_int64();
     const CPubKey key = ParsePubKey(request.params[1]);
 
-    CDataStream ss(ParseHexV(request.params[2], "proof"), SER_NETWORK,
-                   PROTOCOL_VERSION);
     avalanche::Proof proof;
-    ss >> proof;
+    bilingual_str error;
+    if (!avalanche::Proof::FromHex(proof, request.params[2].get_str(), error)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, error.original);
+    }
 
     if (key != proof.getMaster()) {
         // TODO: we want to provide a proper delegation.
@@ -242,11 +243,11 @@
     }
 
     avalanche::Proof proof;
-    {
-        CDataStream ss(ParseHexV(request.params[0], "proof"), SER_NETWORK,
-                       PROTOCOL_VERSION);
-        ss >> proof;
+    bilingual_str error;
+    if (!avalanche::Proof::FromHex(proof, request.params[0].get_str(), error)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, error.original);
     }
+
     avalanche::ProofValidationState proofState;
     if (!proof.verify(proofState)) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "The proof is invalid");