diff --git a/homeassistant/components/device_tracker/nmap_tracker.py b/homeassistant/components/device_tracker/nmap_tracker.py
index e3af9ad5c44..8876ed3d488 100644
--- a/homeassistant/components/device_tracker/nmap_tracker.py
+++ b/homeassistant/components/device_tracker/nmap_tracker.py
@@ -43,6 +43,8 @@ _LOGGER = logging.getLogger(__name__)
 # interval in minutes to exclude devices from a scan while they are home
 CONF_HOME_INTERVAL = "home_interval"
 
+REQUIREMENTS = ['python-libnmap>=0.6.2']
+
 
 def get_scanner(hass, config):
     """ Validates config and returns a Nmap scanner. """
diff --git a/homeassistant/components/light/tellstick.py b/homeassistant/components/light/tellstick.py
index d3c35ae0640..bf74e7a30a9 100644
--- a/homeassistant/components/light/tellstick.py
+++ b/homeassistant/components/light/tellstick.py
@@ -5,6 +5,8 @@ from homeassistant.components.light import Light, ATTR_BRIGHTNESS
 from homeassistant.const import ATTR_FRIENDLY_NAME
 import tellcore.constants as tellcore_constants
 
+REQUIREMENTS = ['tellcore-py>=1.0.4']
+
 
 def setup_platform(hass, config, add_devices_callback, discovery_info=None):
     """ Find and return tellstick lights. """
diff --git a/homeassistant/components/light/wink.py b/homeassistant/components/light/wink.py
index c4a47ca7da1..a703823ae22 100644
--- a/homeassistant/components/light/wink.py
+++ b/homeassistant/components/light/wink.py
@@ -5,6 +5,9 @@ from homeassistant.components.light import ATTR_BRIGHTNESS
 from homeassistant.components.wink import WinkToggleDevice
 from homeassistant.const import CONF_ACCESS_TOKEN
 
+REQUIREMENTS = ['https://github.com/balloob/python-wink/archive/master.zip'
+                '#pywink>=0.1']
+
 
 def setup_platform(hass, config, add_devices_callback, discovery_info=None):
     """ Find and return Wink lights. """
diff --git a/homeassistant/components/modbus.py b/homeassistant/components/modbus.py
index 66b9cedc6d1..0b30a7b5181 100644
--- a/homeassistant/components/modbus.py
+++ b/homeassistant/components/modbus.py
@@ -38,6 +38,7 @@ from homeassistant.const import (EVENT_HOMEASSISTANT_START,
 DOMAIN = "modbus"
 
 DEPENDENCIES = []
+REQUIREMENTS = ['pymodbus>=1.2.0']
 
 # Type of network
 MEDIUM = "type"
diff --git a/homeassistant/components/sensor/modbus.py b/homeassistant/components/sensor/modbus.py
index 31606abf25e..c1cbf101dc2 100644
--- a/homeassistant/components/sensor/modbus.py
+++ b/homeassistant/components/sensor/modbus.py
@@ -57,6 +57,7 @@ from homeassistant.const import (
     STATE_ON, STATE_OFF)
 
 _LOGGER = logging.getLogger(__name__)
+DEPENDENCIES = ['modbus']
 
 
 def setup_platform(hass, config, add_devices, discovery_info=None):
diff --git a/homeassistant/components/sensor/tellstick.py b/homeassistant/components/sensor/tellstick.py
index f80a3c19f12..7d024333023 100644
--- a/homeassistant/components/sensor/tellstick.py
+++ b/homeassistant/components/sensor/tellstick.py
@@ -35,6 +35,8 @@ import homeassistant.util as util
 
 DatatypeDescription = namedtuple("DatatypeDescription", ['name', 'unit'])
 
+REQUIREMENTS = ['tellcore-py>=1.0.4']
+
 
 # pylint: disable=unused-argument
 def setup_platform(hass, config, add_devices, discovery_info=None):
diff --git a/homeassistant/components/sensor/wink.py b/homeassistant/components/sensor/wink.py
index fa758b59568..4056bbd7733 100644
--- a/homeassistant/components/sensor/wink.py
+++ b/homeassistant/components/sensor/wink.py
@@ -8,6 +8,9 @@ import logging
 from homeassistant.helpers.entity import Entity
 from homeassistant.const import CONF_ACCESS_TOKEN, STATE_OPEN, STATE_CLOSED
 
+REQUIREMENTS = ['https://github.com/balloob/python-wink/archive/master.zip'
+                '#pywink>=0.1']
+
 
 def setup_platform(hass, config, add_devices, discovery_info=None):
     """ Sets up the Wink platform. """
diff --git a/homeassistant/components/switch/modbus.py b/homeassistant/components/switch/modbus.py
index 6f518946ed9..dbf9bc83aad 100644
--- a/homeassistant/components/switch/modbus.py
+++ b/homeassistant/components/switch/modbus.py
@@ -38,6 +38,7 @@ import homeassistant.components.modbus as modbus
 from homeassistant.helpers.entity import ToggleEntity
 
 _LOGGER = logging.getLogger(__name__)
+DEPENDENCIES = ['modbus']
 
 
 def setup_platform(hass, config, add_devices, discovery_info=None):
diff --git a/homeassistant/components/switch/tellstick.py b/homeassistant/components/switch/tellstick.py
index 6f9070d28fb..4fde4babf9e 100644
--- a/homeassistant/components/switch/tellstick.py
+++ b/homeassistant/components/switch/tellstick.py
@@ -19,6 +19,8 @@ import tellcore.constants as tellcore_constants
 
 SINGAL_REPETITIONS = 1
 
+REQUIREMENTS = ['tellcore-py>=1.0.4']
+
 
 # pylint: disable=unused-argument
 def setup_platform(hass, config, add_devices_callback, discovery_info=None):
diff --git a/homeassistant/components/switch/wemo.py b/homeassistant/components/switch/wemo.py
index 33f5f03799b..3020f638dd3 100644
--- a/homeassistant/components/switch/wemo.py
+++ b/homeassistant/components/switch/wemo.py
@@ -8,6 +8,8 @@ import logging
 
 from homeassistant.components.switch import SwitchDevice
 
+REQUIREMENTS = ['pywemo>=0.1']
+
 
 # pylint: disable=unused-argument
 def setup_platform(hass, config, add_devices_callback, discovery_info=None):
diff --git a/homeassistant/components/switch/wink.py b/homeassistant/components/switch/wink.py
index 792de50a855..556a40b181f 100644
--- a/homeassistant/components/switch/wink.py
+++ b/homeassistant/components/switch/wink.py
@@ -9,6 +9,9 @@ import logging
 from homeassistant.components.wink import WinkToggleDevice
 from homeassistant.const import CONF_ACCESS_TOKEN
 
+REQUIREMENTS = ['https://github.com/balloob/python-wink/archive/master.zip'
+                '#pywink>=0.1']
+
 
 def setup_platform(hass, config, add_devices, discovery_info=None):
     """ Sets up the Wink platform. """
diff --git a/requirements.txt b/requirements.txt
index 196802fe591..1d4bb5e82b5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -106,3 +106,7 @@ RPi.GPIO >=0.5.11
 
 # PAHO MQTT Binding (protocol.mqtt)
 paho-mqtt>=1.1
+
+# PyModbus (modbus)
+pymodbus>=1.2.0
+