diff --git a/tests/mocks.py b/tests/mocks.py
index 4d7eab9..5097e65 100644
--- a/tests/mocks.py
+++ b/tests/mocks.py
@@ -54,7 +54,7 @@ class MockPopen(object):
         self.mock.returncode = 0
 
     def assert_call(self, cmd):
-        self.mock.popen.assert_called_with(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+        self.mock.popen.assert_any_call(shlex.split(cmd), stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
 
     def cleanup(self):
         self._patch.stop()
diff --git a/tests/modules/test_caffeine.py b/tests/modules/test_caffeine.py
new file mode 100644
index 0000000..6eaf228
--- /dev/null
+++ b/tests/modules/test_caffeine.py
@@ -0,0 +1,69 @@
+# pylint: disable=C0103,C0111
+
+import json
+import unittest
+import mock
+
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
+
+import tests.mocks as mocks
+
+import bumblebee.input
+from bumblebee.config import Config
+from bumblebee.input import I3BarInput, LEFT_MOUSE
+from bumblebee.modules.caffeine import Module
+
+class TestCaffeineModule(unittest.TestCase):
+    def setUp(self):
+        self._stdin, self._select, self.stdin, self.select = mocks.epoll_mock("bumblebee.input")
+
+        self.popen = mocks.MockPopen()
+
+        self.input = I3BarInput()
+        self.engine = mock.Mock()
+        self.config = Config()
+        self.engine.input = self.input
+        self.engine.input.need_event = True
+
+        self.module = Module(engine=self.engine, config={ "config": self.config })
+        for widget in self.module.widgets():
+            widget.link_module(self.module)
+            self.anyWidget = widget
+
+        self.xset_active = "  timeout:  0    cycle:  123"
+        self.xset_inactive = "  timeout:  600    cycle:  123"
+
+    def tearDown(self):
+        self._stdin.stop()
+        self._select.stop()
+        self.popen.cleanup()
+
+    def test_text(self):
+        self.assertEquals(self.module.caffeine(self.anyWidget), "")
+
+    def test_active(self):
+        self.popen.mock.communicate.return_value = (self.xset_active, None)
+        self.assertTrue(not "deactivated" in self.module.state(self.anyWidget))
+        self.assertTrue("activated" in self.module.state(self.anyWidget))
+
+    def test_inactive(self):
+        self.popen.mock.communicate.return_value = (self.xset_inactive, None)
+        self.assertTrue("deactivated" in self.module.state(self.anyWidget))
+        self.popen.mock.communicate.return_value = ("no text", None)
+        self.assertTrue("deactivated" in self.module.state(self.anyWidget))
+
+    def test_toggle(self):
+        self.popen.mock.communicate.return_value = (self.xset_active, None)
+        mocks.mouseEvent(stdin=self.stdin, button=LEFT_MOUSE, inp=self.input, module=self.module)
+        self.popen.assert_call("xset s default")
+        self.popen.assert_call("notify-send \"Out of coffee\"")
+        
+        self.popen.mock.communicate.return_value = (self.xset_inactive, None)
+        mocks.mouseEvent(stdin=self.stdin, button=LEFT_MOUSE, inp=self.input, module=self.module)
+        self.popen.assert_call("xset s off")
+        self.popen.assert_call("notify-send \"Consuming caffeine\"")
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4