diff --git a/bumblebee/engine.py b/bumblebee/engine.py
index e2b4826..2ba5107 100644
--- a/bumblebee/engine.py
+++ b/bumblebee/engine.py
@@ -12,8 +12,14 @@ class Module(object):
     (e.g. CPU utilization, disk usage, etc.) derive from
     this base class.
     """
-    def __init__(self, engine):
-        pass
+    def __init__(self, engine, widgets):
+        self._widgets = []
+        if widgets:
+            self._widgets = widgets if isinstance(widgets, list) else [widgets]
+
+    def widgets(self):
+        """Return the widgets to draw for this module"""
+        return self._widgets
 
 class Engine(object):
     """Engine for driving the application
@@ -53,11 +59,9 @@ class Engine(object):
         """Start the event loop"""
         self._output.start()
         while self.running():
-            widgets = []
             for module in self._modules:
-                module_widgets = module.widgets()
-                widgets += module_widgets if isinstance(module_widgets, list) else [module_widgets]
-            self._output.draw(widgets=widgets, engine=self)
+                module.update(module.widgets())
+                self._output.draw(widgets=module.widgets(), engine=self)
             self._output.flush()
             if self.running():
                 time.sleep(1)
diff --git a/bumblebee/modules/cpu.py b/bumblebee/modules/cpu.py
index ecc2376..dbee32e 100644
--- a/bumblebee/modules/cpu.py
+++ b/bumblebee/modules/cpu.py
@@ -7,12 +7,15 @@ import bumblebee.engine
 
 class Module(bumblebee.engine.Module):
     def __init__(self, engine):
-        super(Module, self).__init__(engine)
+        super(Module, self).__init__(engine,
+            bumblebee.output.Widget(full_text=self.utilization)
+        )
         self._utilization = psutil.cpu_percent(percpu=False)
 
-    def widgets(self):
-        self._utilization = psutil.cpu_percent(percpu=False)
+    def utilization(self):
+        return "{:05.02f}%".format(self._utilization)
 
-        return bumblebee.output.Widget(full_text="{:05.02f}%".format(self._utilization))
+    def update(self, widgets):
+        self._utilization = psutil.cpu_percent(percpu=False)
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
diff --git a/bumblebee/modules/test.py b/bumblebee/modules/test.py
index 94b99c4..61af7e9 100644
--- a/bumblebee/modules/test.py
+++ b/bumblebee/modules/test.py
@@ -6,9 +6,11 @@ import bumblebee.engine
 
 class Module(bumblebee.engine.Module):
     def __init__(self, engine):
-        super(Module, self).__init__(engine)
+        super(Module, self).__init__(engine,
+            bumblebee.output.Widget(full_text="test")
+        )
 
-    def widgets(self):
-        return bumblebee.output.Widget(full_text="test")
+    def update(self, widgets):
+        pass
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
diff --git a/bumblebee/output.py b/bumblebee/output.py
index bd05450..727d634 100644
--- a/bumblebee/output.py
+++ b/bumblebee/output.py
@@ -12,7 +12,10 @@ class Widget(object):
 
     def full_text(self):
         """Retrieve the full text to display in the widget"""
-        return self._full_text
+        if callable(self._full_text):
+            return self._full_text()
+        else:
+            return self._full_text
 
 class I3BarOutput(object):
     """Manage output according to the i3bar protocol"""
diff --git a/bumblebee/theme.py b/bumblebee/theme.py
index e83ea10..e65bc41 100644
--- a/bumblebee/theme.py
+++ b/bumblebee/theme.py
@@ -1,6 +1,7 @@
 """Theme support"""
 
 class Theme(object):
+    """Represents a collection of icons and colors"""
     pass
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
diff --git a/runlint.sh b/runlint.sh
index 0555628..6902ce9 100755
--- a/runlint.sh
+++ b/runlint.sh
@@ -1,3 +1,3 @@
 #!/bin/sh
 
-find . -name "*.py"|xargs pylint --disable=R0903,R0201
+find . -name "*.py"|xargs pylint --disable=R0903,R0201,C0330
diff --git a/tests/modules/test_cpu.py b/tests/modules/test_cpu.py
index 9c3be94..9ec7ecb 100644
--- a/tests/modules/test_cpu.py
+++ b/tests/modules/test_cpu.py
@@ -10,7 +10,14 @@ class TestCPUModule(unittest.TestCase):
         self.module = Module(None)
 
     def test_widgets(self):
-        widget = self.module.widgets()
-        assertWidgetAttributes(self, widget)
+        widgets = self.module.widgets()
+        for widget in widgets:
+            assertWidgetAttributes(self, widget)
+
+    def test_update(self):
+        widgets = self.module.widgets()
+        self.module.update(widgets)
+        self.test_widgets()
+        self.assertEquals(widgets, self.module.widgets())
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4
diff --git a/tests/test_module.py b/tests/test_module.py
new file mode 100644
index 0000000..34aa69d
--- /dev/null
+++ b/tests/test_module.py
@@ -0,0 +1,25 @@
+# pylint: disable=C0103,C0111,W0703
+
+import unittest
+
+from bumblebee.engine import Module
+from tests.util import MockWidget
+
+class TestModule(unittest.TestCase):
+    def setUp(self):
+        self.widget = MockWidget("foo")
+        self.moduleWithoutWidgets = Module(engine=None, widgets=None)
+        self.moduleWithOneWidget = Module(engine=None, widgets=self.widget)
+        self.moduleWithMultipleWidgets = Module(engine=None,
+            widgets=[self.widget, self.widget, self.widget]
+        )
+
+    def test_empty_widgets(self):
+        self.assertEquals(self.moduleWithoutWidgets.widgets(), [])
+
+    def test_single_widget(self):
+        self.assertEquals(self.moduleWithOneWidget.widgets(), [self.widget])
+
+    def test_multiple_widgets(self):
+        for widget in self.moduleWithMultipleWidgets.widgets():
+            self.assertEquals(widget, self.widget)
diff --git a/tests/util.py b/tests/util.py
index 00001d5..e3bef15 100644
--- a/tests/util.py
+++ b/tests/util.py
@@ -23,6 +23,9 @@ class MockWidget(object):
     def __init__(self, text):
         self._text = text
 
+    def update(self, widgets):
+        pass
+
     def full_text(self):
         return self._text