diff --git a/homeassistant/components/zwave_js/__init__.py b/homeassistant/components/zwave_js/__init__.py
index 5d294931e66..b1fc585394e 100644
--- a/homeassistant/components/zwave_js/__init__.py
+++ b/homeassistant/components/zwave_js/__init__.py
@@ -770,3 +770,14 @@ def async_ensure_addon_updated(hass: HomeAssistant) -> None:
     if addon_manager.task_in_progress():
         raise ConfigEntryNotReady
     addon_manager.async_schedule_update_addon(catch_error=True)
+
+
+async def async_migrate_entry(hass: HomeAssistant, config_entry: ConfigEntry) -> bool:
+    """Migrate old entry."""
+    if isinstance(config_entry.unique_id, int):  # type: ignore[unreachable]
+        hass.config_entries.async_update_entry(  # type: ignore[unreachable]
+            config_entry,
+            unique_id=str(config_entry.unique_id),
+        )
+
+    return True
diff --git a/homeassistant/components/zwave_js/config_flow.py b/homeassistant/components/zwave_js/config_flow.py
index c76e0692ad5..609da3390cc 100644
--- a/homeassistant/components/zwave_js/config_flow.py
+++ b/homeassistant/components/zwave_js/config_flow.py
@@ -411,7 +411,7 @@ class ConfigFlow(BaseZwaveJSFlow, config_entries.ConfigFlow, domain=DOMAIN):
             errors["base"] = "unknown"
         else:
             await self.async_set_unique_id(
-                version_info.home_id, raise_on_progress=False
+                str(version_info.home_id), raise_on_progress=False
             )
             # Make sure we disable any add-on handling
             # if the controller is reconfigured in a manual step.
@@ -445,7 +445,7 @@ class ConfigFlow(BaseZwaveJSFlow, config_entries.ConfigFlow, domain=DOMAIN):
         except CannotConnect:
             return self.async_abort(reason="cannot_connect")
 
-        await self.async_set_unique_id(version_info.home_id)
+        await self.async_set_unique_id(str(version_info.home_id))
         self._abort_if_unique_id_configured(updates={CONF_URL: self.ws_address})
 
         return await self.async_step_hassio_confirm()
@@ -579,7 +579,7 @@ class ConfigFlow(BaseZwaveJSFlow, config_entries.ConfigFlow, domain=DOMAIN):
                     raise AbortFlow("cannot_connect") from err
 
             await self.async_set_unique_id(
-                self.version_info.home_id, raise_on_progress=False
+                str(self.version_info.home_id), raise_on_progress=False
             )
 
         self._abort_if_unique_id_configured(
diff --git a/tests/components/zwave_js/test_config_flow.py b/tests/components/zwave_js/test_config_flow.py
index 66fc9934ee1..3e40d67e2a4 100644
--- a/tests/components/zwave_js/test_config_flow.py
+++ b/tests/components/zwave_js/test_config_flow.py
@@ -169,7 +169,7 @@ async def test_manual(hass):
     }
     assert len(mock_setup.mock_calls) == 1
     assert len(mock_setup_entry.mock_calls) == 1
-    assert result2["result"].unique_id == 1234
+    assert result2["result"].unique_id == "1234"
 
 
 async def slow_server_version(*args):
@@ -243,7 +243,7 @@ async def test_manual_already_configured(hass):
             "integration_created_addon": True,
         },
         title=TITLE,
-        unique_id=1234,
+        unique_id="1234",
     )
     entry.add_to_hass(hass)
 
@@ -401,7 +401,10 @@ async def test_abort_discovery_with_existing_entry(
     """Test discovery flow is aborted if an entry already exists."""
 
     entry = MockConfigEntry(
-        domain=DOMAIN, data={"url": "ws://localhost:3000"}, title=TITLE, unique_id=1234
+        domain=DOMAIN,
+        data={"url": "ws://localhost:3000"},
+        title=TITLE,
+        unique_id="1234",
     )
     entry.add_to_hass(hass)
 
@@ -1039,7 +1042,7 @@ async def test_addon_running_already_configured(
             "s2_unauthenticated_key": "old987",
         },
         title=TITLE,
-        unique_id=1234,
+        unique_id="1234",
     )
     entry.add_to_hass(hass)
 
@@ -1370,7 +1373,7 @@ async def test_addon_installed_already_configured(
             "s2_unauthenticated_key": "old987",
         },
         title=TITLE,
-        unique_id=1234,
+        unique_id="1234",
     )
     entry.add_to_hass(hass)
 
diff --git a/tests/components/zwave_js/test_init.py b/tests/components/zwave_js/test_init.py
index 7b3fd773839..9c260eda4c1 100644
--- a/tests/components/zwave_js/test_init.py
+++ b/tests/components/zwave_js/test_init.py
@@ -8,6 +8,7 @@ from zwave_js_server.exceptions import BaseZwaveJSServerError, InvalidServerVers
 from zwave_js_server.model.node import Node
 
 from homeassistant.components.hassio.handler import HassioAPIError
+from homeassistant.components.zwave_js import async_migrate_entry
 from homeassistant.components.zwave_js.const import DOMAIN
 from homeassistant.components.zwave_js.helpers import get_device_id
 from homeassistant.config_entries import ConfigEntryDisabler, ConfigEntryState
@@ -1327,3 +1328,12 @@ async def test_disabled_entity_on_value_removed(hass, zp3111, client, integratio
         | {battery_level_entity, binary_cover_entity, sensor_cover_entity}
         == new_unavailable_entities
     )
+
+
+async def test_async_migrate_entry(hass):
+    """Test async_migrate_entry."""
+    entry = MockConfigEntry(domain=DOMAIN, unique_id=123456789)
+    assert isinstance(entry.unique_id, int)
+    await async_migrate_entry(hass, entry)
+    assert isinstance(entry.unique_id, str)
+    assert entry.unique_id == "123456789"