diff --git a/homeassistant/components/luftdaten/__init__.py b/homeassistant/components/luftdaten/__init__.py
index b00fca7d3c0..45d75b90f7f 100644
--- a/homeassistant/components/luftdaten/__init__.py
+++ b/homeassistant/components/luftdaten/__init__.py
@@ -12,13 +12,14 @@ from homeassistant.config_entries import SOURCE_IMPORT
 from homeassistant.const import (
     CONF_MONITORED_CONDITIONS, CONF_SCAN_INTERVAL, CONF_SENSORS,
     CONF_SHOW_ON_MAP, TEMP_CELSIUS)
+from homeassistant.core import callback
 from homeassistant.exceptions import ConfigEntryNotReady
 from homeassistant.helpers.aiohttp_client import async_get_clientsession
 import homeassistant.helpers.config_validation as cv
 from homeassistant.helpers.dispatcher import async_dispatcher_send
 from homeassistant.helpers.event import async_track_time_interval
 
-from .config_flow import configured_sensors
+from .config_flow import configured_sensors, duplicate_stations
 from .const import CONF_SENSOR_ID, DEFAULT_SCAN_INTERVAL, DOMAIN
 
 REQUIREMENTS = ['luftdaten==0.3.4']
@@ -67,6 +68,14 @@ CONFIG_SCHEMA = vol.Schema({
 }, extra=vol.ALLOW_EXTRA)
 
 
+@callback
+def _async_fixup_sensor_id(hass, config_entry, sensor_id):
+    hass.config_entries.async_update_entry(
+        config_entry, data={
+            **config_entry.data, CONF_SENSOR_ID: int(sensor_id)
+        })
+
+
 async def async_setup(hass, config):
     """Set up the Luftdaten component."""
     hass.data[DOMAIN] = {}
@@ -77,7 +86,7 @@ async def async_setup(hass, config):
         return True
 
     conf = config[DOMAIN]
-    station_id = conf.get(CONF_SENSOR_ID)
+    station_id = conf[CONF_SENSOR_ID]
 
     if station_id not in configured_sensors(hass):
         hass.async_create_task(
@@ -102,6 +111,18 @@ async def async_setup_entry(hass, config_entry):
     from luftdaten import Luftdaten
     from luftdaten.exceptions import LuftdatenError
 
+    if not isinstance(config_entry.data[CONF_SENSOR_ID], int):
+        _async_fixup_sensor_id(hass, config_entry,
+                               config_entry.data[CONF_SENSOR_ID])
+
+    if (config_entry.data[CONF_SENSOR_ID] in
+            duplicate_stations(hass) and config_entry.source == SOURCE_IMPORT):
+        _LOGGER.warning("Removing duplicate sensors for station %s",
+                        config_entry.data[CONF_SENSOR_ID])
+        hass.async_create_task(hass.config_entries.async_remove(
+            config_entry.entry_id))
+        return False
+
     session = async_get_clientsession(hass)
 
     try:
diff --git a/homeassistant/components/luftdaten/config_flow.py b/homeassistant/components/luftdaten/config_flow.py
index 33715c3c0c1..b4ebc93da9c 100644
--- a/homeassistant/components/luftdaten/config_flow.py
+++ b/homeassistant/components/luftdaten/config_flow.py
@@ -7,6 +7,7 @@ from homeassistant import config_entries
 from homeassistant.const import CONF_SCAN_INTERVAL, CONF_SHOW_ON_MAP
 from homeassistant.core import callback
 from homeassistant.helpers import aiohttp_client
+import homeassistant.helpers.config_validation as cv
 
 from .const import CONF_SENSOR_ID, DEFAULT_SCAN_INTERVAL, DOMAIN
 
@@ -15,10 +16,18 @@ from .const import CONF_SENSOR_ID, DEFAULT_SCAN_INTERVAL, DOMAIN
 def configured_sensors(hass):
     """Return a set of configured Luftdaten sensors."""
     return set(
-        '{0}'.format(entry.data[CONF_SENSOR_ID])
+        entry.data[CONF_SENSOR_ID]
         for entry in hass.config_entries.async_entries(DOMAIN))
 
 
+@callback
+def duplicate_stations(hass):
+    """Return a set of duplicate configured Luftdaten stations."""
+    stations = [int(entry.data[CONF_SENSOR_ID])
+                for entry in hass.config_entries.async_entries(DOMAIN)]
+    return {x for x in stations if stations.count(x) > 1}
+
+
 @config_entries.HANDLERS.register(DOMAIN)
 class LuftDatenFlowHandler(config_entries.ConfigFlow):
     """Handle a Luftdaten config flow."""
@@ -30,7 +39,7 @@ class LuftDatenFlowHandler(config_entries.ConfigFlow):
     def _show_form(self, errors=None):
         """Show the form to the user."""
         data_schema = OrderedDict()
-        data_schema[vol.Required(CONF_SENSOR_ID)] = str
+        data_schema[vol.Required(CONF_SENSOR_ID)] = cv.positive_int
         data_schema[vol.Optional(CONF_SHOW_ON_MAP, default=False)] = bool
 
         return self.async_show_form(
@@ -72,4 +81,4 @@ class LuftDatenFlowHandler(config_entries.ConfigFlow):
             CONF_SCAN_INTERVAL, DEFAULT_SCAN_INTERVAL)
         user_input.update({CONF_SCAN_INTERVAL: scan_interval.seconds})
 
-        return self.async_create_entry(title=sensor_id, data=user_input)
+        return self.async_create_entry(title=str(sensor_id), data=user_input)