diff --git a/homeassistant/components/rainmachine/__init__.py b/homeassistant/components/rainmachine/__init__.py
index 0e0dd726f75..5ffdc7951db 100644
--- a/homeassistant/components/rainmachine/__init__.py
+++ b/homeassistant/components/rainmachine/__init__.py
@@ -344,10 +344,9 @@ async def async_migrate_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     if version == 1:
         version = entry.version = 2
 
-        ent_reg = er.async_get(hass)
-        for entity_entry in [
-            e for e in ent_reg.entities.values() if e.config_entry_id == entry.entry_id
-        ]:
+        @callback
+        def migrate_unique_id(entity_entry: er.RegistryEntry) -> dict[str, Any]:
+            """Migrate the unique ID to a new format."""
             unique_id_pieces = entity_entry.unique_id.split("_")
             old_mac = unique_id_pieces[0]
             new_mac = ":".join(old_mac[i : i + 2] for i in range(0, len(old_mac), 2))
@@ -356,9 +355,9 @@ async def async_migrate_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
             if entity_entry.entity_id.startswith("switch"):
                 unique_id_pieces[1] = unique_id_pieces[1][11:].lower()
 
-            ent_reg.async_update_entity(
-                entity_entry.entity_id, new_unique_id="_".join(unique_id_pieces)
-            )
+            return {"new_unique_id": "_".join(unique_id_pieces)}
+
+        await er.async_migrate_entries(hass, entry.entry_id, migrate_unique_id)
 
     LOGGER.info("Migration to version %s successful", version)