diff --git a/src/backend/replication/logical/proto.c b/src/backend/replication/logical/proto.c
index f5f2bc24d8..a041937ce9 100644
--- a/src/backend/replication/logical/proto.c
+++ b/src/backend/replication/logical/proto.c
@@ -1194,9 +1194,11 @@ logicalrep_read_stream_abort(StringInfo in, TransactionId *xid,
 /*
  * Get string representing LogicalRepMsgType.
  */
-char *
+const char *
 logicalrep_message_type(LogicalRepMsgType action)
 {
+	static char	err_unknown[20];
+
 	switch (action)
 	{
 		case LOGICAL_REP_MSG_BEGIN:
@@ -1239,7 +1241,12 @@ logicalrep_message_type(LogicalRepMsgType action)
 			return "STREAM PREPARE";
 	}
 
-	elog(ERROR, "invalid logical replication message type \"%c\"", action);
+	/*
+	 * This message provides context in the error raised when applying a
+	 * logical message. So we can't throw an error here. Return an unknown
+	 * indicator value so that the original error is still reported.
+	 */
+	snprintf(err_unknown, sizeof(err_unknown), "??? (%d)", action);
 
-	return NULL;				/* keep compiler quiet */
+	return err_unknown;
 }
diff --git a/src/backend/replication/logical/worker.c b/src/backend/replication/logical/worker.c
index cc6b079fcd..dcc3fdf6c7 100644
--- a/src/backend/replication/logical/worker.c
+++ b/src/backend/replication/logical/worker.c
@@ -2579,7 +2579,7 @@ apply_dispatch(StringInfo s)
 		default:
 			ereport(ERROR,
 					(errcode(ERRCODE_PROTOCOL_VIOLATION),
-					 errmsg("invalid logical replication message type \"%c\"", action)));
+					 errmsg("invalid logical replication message type \"??? (%d)\"", action)));
 	}
 
 	/* Reset the current command */
diff --git a/src/include/replication/logicalproto.h b/src/include/replication/logicalproto.h
index 04e1cd89cf..8cdc04a65f 100644
--- a/src/include/replication/logicalproto.h
+++ b/src/include/replication/logicalproto.h
@@ -249,6 +249,6 @@ extern void logicalrep_write_stream_abort(StringInfo out, TransactionId xid,
 										  TransactionId subxid);
 extern void logicalrep_read_stream_abort(StringInfo in, TransactionId *xid,
 										 TransactionId *subxid);
-extern char *logicalrep_message_type(LogicalRepMsgType action);
+extern const char *logicalrep_message_type(LogicalRepMsgType action);
 
 #endif							/* LOGICAL_PROTO_H */