diff --git a/pgxn/neon/walproposer.c b/pgxn/neon/walproposer.c
index 9bfdfea6dc..e967419282 100644
--- a/pgxn/neon/walproposer.c
+++ b/pgxn/neon/walproposer.c
@@ -1774,7 +1774,7 @@ HandleSafekeeperResponse(WalProposer *wp, Safekeeper *fromsk)
 static void
 MembershipConfigurationSerialize(MembershipConfiguration *mconf, StringInfo buf)
 {
-	int			i;
+	uint32		i;
 
 	pq_sendint32(buf, mconf->generation);
 
@@ -1808,8 +1808,8 @@ PAMessageSerialize(WalProposer *wp, ProposerAcceptorMessage *msg, StringInfo buf
 
 	resetStringInfo(buf);
 
+	/* removeme tag check after converting all msgs */
 	if (proto_version == 3 && msg->tag == 'g')
-		//removeme tag check after converting all msgs
 	{
 		/*
 		 * v2 sends structs for some messages as is, so commonly send tag only
@@ -1838,8 +1838,9 @@ PAMessageSerialize(WalProposer *wp, ProposerAcceptorMessage *msg, StringInfo buf
 		return;
 	}
 
-	if (proto_version == 2 || proto_version == 3) // TODO remove proto_version == 3 after converting all msgs
-		//removeme tag check after converting all msgs
+	if (proto_version == 2 || proto_version == 3)
+		//TODO remove proto_version == 3 after converting all msgs
+		/* removeme tag check after converting all msgs */
 	{
 		switch (msg->tag)
 		{
@@ -1938,82 +1939,99 @@ AsyncReadMessage(Safekeeper *sk, AcceptorProposerMessage *anymsg)
 
 	char	   *buf;
 	int			buf_size;
-	uint64		tag;
+	uint8		tag;
 	StringInfoData s;
 
 	if (!(AsyncRead(sk, &buf, &buf_size)))
 		return false;
+	sk->latestMsgReceivedAt = wp->api.get_current_timestamp(wp);
 
 	/* parse it */
 	s.data = buf;
 	s.len = buf_size;
 	s.cursor = 0;
 
-	tag = pq_getmsgint64_le(&s);
-	if (tag != anymsg->tag)
+	/* removeme tag check after converting all msgs */
+	if (wp->config->proto_version == 3 && anymsg->tag == 'g')
 	{
-		wp_log(WARNING, "unexpected message tag %c from node %s:%s in state %s", (char) tag, sk->host,
-			   sk->port, FormatSafekeeperState(sk));
-		ResetConnection(sk);
-		return false;
+		tag = pq_getmsgint(&s, 1);
+		if (tag != anymsg->tag)
+		{
+			wp_log(WARNING, "unexpected message tag %c from node %s:%s in state %s", (char) tag, sk->host,
+				   sk->port, FormatSafekeeperState(sk));
+			ResetConnection(sk);
+			return false;
+		}
 	}
-	sk->latestMsgReceivedAt = wp->api.get_current_timestamp(wp);
-	switch (tag)
+	/* removeme tag check after converting all msgs */
+	else if (wp->config->proto_version == 2 || wp->config->proto_version == 3)
 	{
-		case 'g':
-			{
-				AcceptorGreeting *msg = (AcceptorGreeting *) anymsg;
-
-				msg->term = pq_getmsgint64_le(&s);
-				msg->nodeId = pq_getmsgint64_le(&s);
-				pq_getmsgend(&s);
-				return true;
-			}
-
-		case 'v':
-			{
-				VoteResponse *msg = (VoteResponse *) anymsg;
-
-				msg->term = pq_getmsgint64_le(&s);
-				msg->voteGiven = pq_getmsgint64_le(&s);
-				msg->flushLsn = pq_getmsgint64_le(&s);
-				msg->truncateLsn = pq_getmsgint64_le(&s);
-				msg->termHistory.n_entries = pq_getmsgint32_le(&s);
-				msg->termHistory.entries = palloc(sizeof(TermSwitchEntry) * msg->termHistory.n_entries);
-				for (int i = 0; i < msg->termHistory.n_entries; i++)
+		tag = pq_getmsgint64_le(&s);
+		if (tag != anymsg->tag)
+		{
+			wp_log(WARNING, "unexpected message tag %c from node %s:%s in state %s", (char) tag, sk->host,
+				   sk->port, FormatSafekeeperState(sk));
+			ResetConnection(sk);
+			return false;
+		}
+		switch (tag)
+		{
+			case 'g':
 				{
-					msg->termHistory.entries[i].term = pq_getmsgint64_le(&s);
-					msg->termHistory.entries[i].lsn = pq_getmsgint64_le(&s);
+					AcceptorGreeting *msg = (AcceptorGreeting *) anymsg;
+
+					msg->term = pq_getmsgint64_le(&s);
+					msg->nodeId = pq_getmsgint64_le(&s);
+					pq_getmsgend(&s);
+					return true;
 				}
-				msg->timelineStartLsn = pq_getmsgint64_le(&s);
-				pq_getmsgend(&s);
-				return true;
-			}
 
-		case 'a':
-			{
-				AppendResponse *msg = (AppendResponse *) anymsg;
+			case 'v':
+				{
+					VoteResponse *msg = (VoteResponse *) anymsg;
 
-				msg->term = pq_getmsgint64_le(&s);
-				msg->flushLsn = pq_getmsgint64_le(&s);
-				msg->commitLsn = pq_getmsgint64_le(&s);
-				msg->hs.ts = pq_getmsgint64_le(&s);
-				msg->hs.xmin.value = pq_getmsgint64_le(&s);
-				msg->hs.catalog_xmin.value = pq_getmsgint64_le(&s);
-				if (s.len > s.cursor)
-					ParsePageserverFeedbackMessage(wp, &s, &msg->ps_feedback);
-				else
-					msg->ps_feedback.present = false;
-				pq_getmsgend(&s);
-				return true;
-			}
+					msg->term = pq_getmsgint64_le(&s);
+					msg->voteGiven = pq_getmsgint64_le(&s);
+					msg->flushLsn = pq_getmsgint64_le(&s);
+					msg->truncateLsn = pq_getmsgint64_le(&s);
+					msg->termHistory.n_entries = pq_getmsgint32_le(&s);
+					msg->termHistory.entries = palloc(sizeof(TermSwitchEntry) * msg->termHistory.n_entries);
+					for (int i = 0; i < msg->termHistory.n_entries; i++)
+					{
+						msg->termHistory.entries[i].term = pq_getmsgint64_le(&s);
+						msg->termHistory.entries[i].lsn = pq_getmsgint64_le(&s);
+					}
+					msg->timelineStartLsn = pq_getmsgint64_le(&s);
+					pq_getmsgend(&s);
+					return true;
+				}
 
-		default:
-			{
-				Assert(false);
-				return false;
-			}
+			case 'a':
+				{
+					AppendResponse *msg = (AppendResponse *) anymsg;
+
+					msg->term = pq_getmsgint64_le(&s);
+					msg->flushLsn = pq_getmsgint64_le(&s);
+					msg->commitLsn = pq_getmsgint64_le(&s);
+					msg->hs.ts = pq_getmsgint64_le(&s);
+					msg->hs.xmin.value = pq_getmsgint64_le(&s);
+					msg->hs.catalog_xmin.value = pq_getmsgint64_le(&s);
+					if (s.len > s.cursor)
+						ParsePageserverFeedbackMessage(wp, &s, &msg->ps_feedback);
+					else
+						msg->ps_feedback.present = false;
+					pq_getmsgend(&s);
+					return true;
+				}
+
+			default:
+				{
+					wp_log(FATAL, "unexpected message tag %c", (char) tag);
+					return false;
+				}
+		}
 	}
+	wp_log(FATAL, "unsupported proto_version %d", wp->config->proto_version);
 }
 
 /*
diff --git a/pgxn/neon/walproposer.h b/pgxn/neon/walproposer.h
index 8a4897cbf7..8a9d99b8c0 100644
--- a/pgxn/neon/walproposer.h
+++ b/pgxn/neon/walproposer.h
@@ -219,7 +219,7 @@ typedef struct ProposerGreetingV2
 
 typedef struct AcceptorProposerMessage
 {
-	uint64		tag;
+	uint8		tag;
 } AcceptorProposerMessage;
 
 /*
diff --git a/safekeeper/src/receive_wal.rs b/safekeeper/src/receive_wal.rs
index c9a92e8ca0..a94e6930e1 100644
--- a/safekeeper/src/receive_wal.rs
+++ b/safekeeper/src/receive_wal.rs
@@ -281,7 +281,7 @@ impl SafekeeperPostgresHandler {
             tokio::select! {
                 // todo: add read|write .context to these errors
                 r = network_reader.run(msg_tx, msg_rx, reply_tx, timeline, next_msg) => r,
-                r = network_write(pgb, reply_rx, pageserver_feedback_rx) => r,
+                r = network_write(pgb, reply_rx, pageserver_feedback_rx, proto_version) => r,
                 _ = timeline_cancel.cancelled() => {
                     return Err(CopyStreamHandlerEnd::Cancelled);
                 }
@@ -459,6 +459,7 @@ async fn network_write<IO: AsyncRead + AsyncWrite + Unpin>(
     pgb_writer: &mut PostgresBackend<IO>,
     mut reply_rx: Receiver<AcceptorProposerMessage>,
     mut pageserver_feedback_rx: tokio::sync::broadcast::Receiver<PageserverFeedback>,
+    proto_version: u32,
 ) -> Result<(), CopyStreamHandlerEnd> {
     let mut buf = BytesMut::with_capacity(128);
 
@@ -496,7 +497,7 @@ async fn network_write<IO: AsyncRead + AsyncWrite + Unpin>(
         };
 
         buf.clear();
-        msg.serialize(&mut buf)?;
+        msg.serialize(&mut buf, proto_version)?;
         pgb_writer.write_message(&BeMessage::CopyData(&buf)).await?;
     }
 }
diff --git a/safekeeper/src/safekeeper.rs b/safekeeper/src/safekeeper.rs
index 7022aa309a..db674d09c8 100644
--- a/safekeeper/src/safekeeper.rs
+++ b/safekeeper/src/safekeeper.rs
@@ -34,7 +34,8 @@ use utils::{
     lsn::Lsn,
 };
 
-pub const SK_PROTOCOL_VERSION: u32 = 2;
+pub const SK_PROTO_VERSION_2: u32 = 2;
+pub const SK_PROTO_VERSION_3: u32 = 3;
 pub const UNKNOWN_SERVER_VERSION: u32 = 0;
 
 #[derive(Debug, Clone, Copy, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
@@ -447,7 +448,7 @@ impl ProposerAcceptorMessage {
     pub fn parse(mut msg_bytes: Bytes, proto_version: u32) -> Result<ProposerAcceptorMessage> {
         // TODO remove after converting all msgs
         let t = msg_bytes[0] as char;
-        if proto_version == 3 && t == 'g' {
+        if proto_version == SK_PROTO_VERSION_3 && t == 'g' {
             if msg_bytes.is_empty() {
                 bail!("ProposerAcceptorMessage is not complete: missing tag");
             }
@@ -483,7 +484,7 @@ impl ProposerAcceptorMessage {
                 _ => bail!("unknown proposer-acceptor message tag: {}", tag),
             }
         // TODO remove proto_version == 3 after converting all msgs
-        } else if proto_version == 2 || proto_version == 3 {
+        } else if proto_version == SK_PROTO_VERSION_2 || proto_version == SK_PROTO_VERSION_3 {
             // xxx using Reader is inefficient but easy to work with bincode
             let mut stream = msg_bytes.reader();
             // u64 is here to avoid padding; it will be removed once we stop packing C structs into the wire as is
@@ -624,44 +625,55 @@ pub enum AcceptorProposerMessage {
 
 impl AcceptorProposerMessage {
     /// Serialize acceptor -> proposer message.
-    pub fn serialize(&self, buf: &mut BytesMut) -> Result<()> {
-        match self {
-            AcceptorProposerMessage::Greeting(msg) => {
-                buf.put_u64_le('g' as u64);
-                buf.put_u64_le(msg.term);
-                buf.put_u64_le(msg.node_id.0);
+    pub fn serialize(&self, buf: &mut BytesMut, proto_version: u32) -> Result<()> {
+        // TODO remove after converting all msgs
+        if proto_version == SK_PROTO_VERSION_3
+            && (matches!(self, AcceptorProposerMessage::Greeting(_)))
+        {
+            match self {
+                _ => bail!("not implemented"),
             }
-            AcceptorProposerMessage::VoteResponse(msg) => {
-                buf.put_u64_le('v' as u64);
-                buf.put_u64_le(msg.term);
-                buf.put_u64_le(msg.vote_given);
-                buf.put_u64_le(msg.flush_lsn.into());
-                buf.put_u64_le(msg.truncate_lsn.into());
-                buf.put_u32_le(msg.term_history.0.len() as u32);
-                for e in &msg.term_history.0 {
-                    buf.put_u64_le(e.term);
-                    buf.put_u64_le(e.lsn.into());
+        // TODO remove 3 after converting all msgs
+        } else if proto_version == SK_PROTO_VERSION_2 || proto_version == SK_PROTO_VERSION_3 {
+            match self {
+                AcceptorProposerMessage::Greeting(msg) => {
+                    buf.put_u64_le('g' as u64);
+                    buf.put_u64_le(msg.term);
+                    buf.put_u64_le(msg.node_id.0);
                 }
-                buf.put_u64_le(msg.timeline_start_lsn.into());
-            }
-            AcceptorProposerMessage::AppendResponse(msg) => {
-                buf.put_u64_le('a' as u64);
-                buf.put_u64_le(msg.term);
-                buf.put_u64_le(msg.flush_lsn.into());
-                buf.put_u64_le(msg.commit_lsn.into());
-                buf.put_i64_le(msg.hs_feedback.ts);
-                buf.put_u64_le(msg.hs_feedback.xmin);
-                buf.put_u64_le(msg.hs_feedback.catalog_xmin);
+                AcceptorProposerMessage::VoteResponse(msg) => {
+                    buf.put_u64_le('v' as u64);
+                    buf.put_u64_le(msg.term);
+                    buf.put_u64_le(msg.vote_given);
+                    buf.put_u64_le(msg.flush_lsn.into());
+                    buf.put_u64_le(msg.truncate_lsn.into());
+                    buf.put_u32_le(msg.term_history.0.len() as u32);
+                    for e in &msg.term_history.0 {
+                        buf.put_u64_le(e.term);
+                        buf.put_u64_le(e.lsn.into());
+                    }
+                    buf.put_u64_le(msg.timeline_start_lsn.into());
+                }
+                AcceptorProposerMessage::AppendResponse(msg) => {
+                    buf.put_u64_le('a' as u64);
+                    buf.put_u64_le(msg.term);
+                    buf.put_u64_le(msg.flush_lsn.into());
+                    buf.put_u64_le(msg.commit_lsn.into());
+                    buf.put_i64_le(msg.hs_feedback.ts);
+                    buf.put_u64_le(msg.hs_feedback.xmin);
+                    buf.put_u64_le(msg.hs_feedback.catalog_xmin);
 
-                // AsyncReadMessage in walproposer.c will not try to decode pageserver_feedback
-                // if it is not present.
-                if let Some(ref msg) = msg.pageserver_feedback {
-                    msg.serialize(buf);
+                    // AsyncReadMessage in walproposer.c will not try to decode pageserver_feedback
+                    // if it is not present.
+                    if let Some(ref msg) = msg.pageserver_feedback {
+                        msg.serialize(buf);
+                    }
                 }
             }
+            Ok(())
+        } else {
+            bail!("unsupported protocol version {}", proto_version);
         }
-
-        Ok(())
     }
 }