diff --git a/homeassistant/components/squeezebox/media_player.py b/homeassistant/components/squeezebox/media_player.py
index 969a07f1fba3..54aa930e35de 100644
--- a/homeassistant/components/squeezebox/media_player.py
+++ b/homeassistant/components/squeezebox/media_player.py
@@ -160,7 +160,7 @@ async def async_setup_entry(
             model=model,
             manufacturer=manufacturer,
             model_id=model_id,
-            hw_version=player.firmware,
+            hw_version=str(player.firmware) if player.firmware is not None else None,
             sw_version=sw_version,
             via_device=(DOMAIN, coordinator.server_uuid),
         )
diff --git a/tests/components/squeezebox/test_init.py b/tests/components/squeezebox/test_init.py
index 08004040ab15..d43e92582b1d 100644
--- a/tests/components/squeezebox/test_init.py
+++ b/tests/components/squeezebox/test_init.py
@@ -123,6 +123,25 @@ async def test_device_registry(
     assert reg_device == snapshot
 
 
+async def test_device_registry_numeric_firmware(
+    hass: HomeAssistant,
+    device_registry: DeviceRegistry,
+    config_entry: MockConfigEntry,
+    lms: MagicMock,
+) -> None:
+    """Test that numeric firmware values are stored as strings in the device registry."""
+    players = await lms.async_get_players()
+    players[0].firmware = 137
+
+    with patch("homeassistant.components.squeezebox.Server", return_value=lms):
+        await hass.config_entries.async_setup(config_entry.entry_id)
+        await hass.async_block_till_done()
+
+    reg_device = device_registry.async_get_device(identifiers={(DOMAIN, TEST_MAC[0])})
+    assert reg_device is not None
+    assert reg_device.hw_version == "137"
+
+
 async def test_device_registry_server_merged(
     hass: HomeAssistant,
     device_registry: DeviceRegistry,