diff --git a/custom_components/tinxylocal/__init__.py b/custom_components/tinxylocal/__init__.py
index 2aeeb7c..7789d6e 100644
--- a/custom_components/tinxylocal/__init__.py
+++ b/custom_components/tinxylocal/__init__.py
@@ -7,7 +7,9 @@
 from homeassistant.config_entries import ConfigEntry
 from homeassistant.const import CONF_HOST, Platform
 from homeassistant.core import HomeAssistant
+from homeassistant.helpers import entity_registry as er
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
+from homeassistant.util import slugify
 
 from .const import (
     CONF_DEVICE,
@@ -34,6 +36,40 @@
 ]
 
 
+def _async_repair_doubled_entity_ids(hass: HomeAssistant, entry: ConfigEntry) -> None:
+    """Strip a duplicated device name from generated entity ids.
+
+    Upgrading from 2.x produced ids like `sensor.hall_hall_ip_address`: the
+    device name appears twice. Fresh installs are unaffected. On one instance,
+    same version, a device added fresh got `sensor.hub_ip_address` while three
+    upgraded ones doubled, so it is specific to that upgrade rather than to the
+    sensor code.
+
+    It has not been reproduced outside a real upgraded instance, so this repairs
+    the result rather than the cause. The rename keeps the unique_id, so recorder
+    history follows the entity. Only entities this integration created are
+    touched, only where the doubled prefix is present, and only when the
+    corrected id is free.
+    """
+    registry = er.async_get(hass)
+    for item in er.async_entries_for_config_entry(registry, entry.entry_id):
+        if not item.has_entity_name:
+            continue
+
+        domain, _, object_id = item.entity_id.partition(".")
+        prefix = slugify(entry.title)
+        doubled = f"{prefix}_{prefix}_"
+        if not object_id.startswith(doubled):
+            continue
+
+        fixed = f"{domain}.{object_id.replace(doubled, f'{prefix}_', 1)}"
+        if registry.async_get(fixed):
+            continue
+
+        _LOGGER.info("Renaming %s to %s", item.entity_id, fixed)
+        registry.async_update_entity(item.entity_id, new_entity_id=fixed)
+
+
 def _async_migrate_entry(hass: HomeAssistant, entry: ConfigEntry) -> None:
     """Bring entries created before 3.0.0 up to date, in place.
 
@@ -61,6 +97,7 @@ async def async_setup_entry(hass: HomeAssistant, entry: TinxyConfigEntry) -> boo
     """Set up Tinxy from a config entry."""
 
     _async_migrate_entry(hass, entry)
+    _async_repair_doubled_entity_ids(hass, entry)
 
     web_session = async_get_clientsession(hass)
 
diff --git a/custom_components/tinxylocal/manifest.json b/custom_components/tinxylocal/manifest.json
index e2fc3e2..12d6132 100644
--- a/custom_components/tinxylocal/manifest.json
+++ b/custom_components/tinxylocal/manifest.json
@@ -11,7 +11,7 @@
   "iot_class": "local_polling",
   "issue_tracker": "https://github.com/arevindh/tinxylocal/issues",
   "requirements": [],
-  "version": "3.0.0b1",
+  "version": "3.0.0b2",
   "zeroconf": [
     {
       "name": "tinxy*",
diff --git a/tests/test_init.py b/tests/test_init.py
index eb3bec0..0b93c52 100644
--- a/tests/test_init.py
+++ b/tests/test_init.py
@@ -91,3 +91,55 @@ async def test_options_are_applied_to_the_hub(
     # the coordinator must poll through the same hubs the platforms command
     assert coordinator.hubs[0].request_timeout == 9
     assert coordinator.hubs[0].rate_limit_delay == 3
+
+
+async def test_doubled_entity_ids_are_repaired(
+    hass: HomeAssistant, device_online: AiohttpClientMocker
+) -> None:
+    """Upgrading from 2.x produced ids with the device name twice.
+
+    The entity keeps its unique_id, so recorder history follows it across.
+    """
+    from homeassistant.helpers import entity_registry as er
+
+    from .const import DEVICE_ID
+
+    entry = MockConfigEntry(
+        domain=DOMAIN, data=ENTRY_DATA, unique_id=CHIP_ID, title="Hall"
+    )
+    entry.add_to_hass(hass)
+
+    registry = er.async_get(hass)
+    broken = registry.async_get_or_create(
+        "sensor",
+        DOMAIN,
+        f"{DEVICE_ID}_ip",
+        config_entry=entry,
+        original_name="IP address",
+        has_entity_name=True,
+        suggested_object_id="hall_hall_ip_address",
+    )
+    assert broken.entity_id == "sensor.hall_hall_ip_address"
+
+    assert await hass.config_entries.async_setup(entry.entry_id)
+    await hass.async_block_till_done()
+
+    assert registry.async_get("sensor.hall_hall_ip_address") is None
+    fixed = registry.async_get("sensor.hall_ip_address")
+    assert fixed is not None
+    assert fixed.unique_id == f"{DEVICE_ID}_ip"
+
+
+async def test_repair_leaves_correct_ids_alone(
+    hass: HomeAssistant, loaded_entry: MockConfigEntry
+) -> None:
+    """A fresh install must not be touched by the repair."""
+    from homeassistant.helpers import entity_registry as er
+
+    registry = er.async_get(hass)
+    ids = {
+        e.entity_id
+        for e in er.async_entries_for_config_entry(registry, loaded_entry.entry_id)
+    }
+    assert "sensor.hall_ip_address" in ids
+    assert not any(".hall_hall_" in i for i in ids)