diff --git a/repeater/main.py b/repeater/main.py
index 22629c9..ab0a206 100644
--- a/repeater/main.py
+++ b/repeater/main.py
@@ -1,5 +1,6 @@
 import asyncio
 import functools
+import inspect
 import logging
 import os
 import signal
@@ -780,6 +781,17 @@ class RepeaterDaemon:
                 limit=retention or 100,
             )
             loaded_messages = len(message_rows)
+            # openhop_core < the sender_prefix change (paired with fd43d86) has no
+            # QueuedMessage.sender_prefix; drop the prefix there instead of failing init.
+            supports_sender_prefix = "sender_prefix" in inspect.signature(QueuedMessage).parameters
+            if message_rows and not supports_sender_prefix:
+                logger.warning(
+                    "Companion %s ('%s'): installed openhop_core QueuedMessage has no "
+                    "sender_prefix field; persisted sender prefixes will be dropped "
+                    "(update openhop_core to restore signed room-post authors)",
+                    companion_hash_str,
+                    name,
+                )
             for msg_dict in message_rows:
                 sk = msg_dict.get("sender_key", b"")
                 if isinstance(sk, str):
@@ -787,18 +799,18 @@ class RepeaterDaemon:
                 sp = msg_dict.get("sender_prefix", b"")
                 if isinstance(sp, str):
                     sp = bytes.fromhex(sp) if sp else b""
-                bridge.message_queue.push(
-                    QueuedMessage(
-                        sender_key=sk,
-                        txt_type=msg_dict.get("txt_type", 0),
-                        timestamp=msg_dict.get("timestamp", 0),
-                        text=msg_dict.get("text", ""),
-                        is_channel=bool(msg_dict.get("is_channel", False)),
-                        channel_idx=msg_dict.get("channel_idx", 0),
-                        path_len=msg_dict.get("path_len", 0),
-                        sender_prefix=sp,
-                    )
+                msg_kwargs = dict(
+                    sender_key=sk,
+                    txt_type=msg_dict.get("txt_type", 0),
+                    timestamp=msg_dict.get("timestamp", 0),
+                    text=msg_dict.get("text", ""),
+                    is_channel=bool(msg_dict.get("is_channel", False)),
+                    channel_idx=msg_dict.get("channel_idx", 0),
+                    path_len=msg_dict.get("path_len", 0),
                 )
+                if supports_sender_prefix:
+                    msg_kwargs["sender_prefix"] = sp
+                bridge.message_queue.push(QueuedMessage(**msg_kwargs))
 
         logger.info(
             "Companion %s ('%s'): restored %d/%d contact(s), %d/%d channel(s), "
diff --git a/tests/test_companion_state_load.py b/tests/test_companion_state_load.py
index a79d548..e30f5a8 100644
--- a/tests/test_companion_state_load.py
+++ b/tests/test_companion_state_load.py
@@ -128,6 +128,41 @@ class TestRestoreCompanionState:
             await daemon._restore_companion_state(sqlite, bridge, _HASH, _NAME)
         assert any("rejected persisted channel" in r.message for r in caplog.records)
 
+    @pytest.mark.asyncio
+    async def test_old_core_without_sender_prefix_drops_prefix(self, caplog):
+        # openhop_core releases before the sender_prefix change reject the kwarg;
+        # message restore must degrade (drop the prefix) instead of failing init.
+        from dataclasses import dataclass, field
+
+        @dataclass
+        class LegacyQueuedMessage:
+            sender_key: bytes = b""
+            txt_type: int = 0
+            timestamp: int = 0
+            text: str = ""
+            is_channel: bool = False
+            channel_idx: int = 0
+            path_len: int = 0
+            snr: float = 0.0
+            rssi: int = 0
+            channel_data_payload: bytes = field(default=b"")
+
+        daemon = self._daemon()
+        bridge = self._bridge()
+        sqlite = self._sqlite(
+            messages=[{"sender_key": b"", "text": "hi", "sender_prefix": b"\xab\xcd"}]
+        )
+        with (
+            patch("openhop_core.companion.models.QueuedMessage", LegacyQueuedMessage),
+            caplog.at_level(logging.WARNING),
+        ):
+            await daemon._restore_companion_state(sqlite, bridge, _HASH, _NAME)
+        bridge.message_queue.push.assert_called_once()
+        pushed = bridge.message_queue.push.call_args[0][0]
+        assert isinstance(pushed, LegacyQueuedMessage)
+        assert pushed.text == "hi"
+        assert any("sender prefixes will be dropped" in r.message for r in caplog.records)
+
     @pytest.mark.asyncio
     async def test_zero_retention_skips_message_load(self):
         daemon = self._daemon()