diff --git a/doc/api/iodevices_ev3.inc b/doc/api/iodevices_ev3.inc
index 552bb30..674a77a 100644
--- a/doc/api/iodevices_ev3.inc
+++ b/doc/api/iodevices_ev3.inc
@@ -67,14 +67,14 @@ DC Motor
 
 This class can be used to control classic LEGO motors using converter cables.
 
-.. autoclass:: pybricks.builtins.DCMotor
+.. autoclass:: pybricks._common.DCMotor
     :noindex:
     :no-members:
 
-    .. automethod:: pybricks.builtins.DCMotor.dc
+    .. automethod:: pybricks._common.DCMotor.dc
         :noindex:
 
-    .. automethod:: pybricks.builtins.DCMotor.stop
+    .. automethod:: pybricks._common.DCMotor.stop
         :noindex:
 
 Ev3dev sensors
diff --git a/doc/api/motors.rst b/doc/api/motors.rst
index 65da141..3cb4625 100644
--- a/doc/api/motors.rst
+++ b/doc/api/motors.rst
@@ -117,21 +117,21 @@ you can set the settings at the beginning of your program. Alternatively, first
 call ``stop()`` to make your ``Motor`` or ``DriveBase`` stop, and then change
 the settings.
 
-.. autoclass:: pybricks.builtins.Control
+.. autoclass:: pybricks._common.Control
     :no-members:
 
     .. rubric:: Status
 
-    .. automethod:: pybricks.builtins.Control.done
+    .. automethod:: pybricks._common.Control.done
 
-    .. automethod:: pybricks.builtins.Control.stalled
+    .. automethod:: pybricks._common.Control.stalled
 
     .. rubric:: Settings
 
-    .. automethod:: pybricks.builtins.Control.limits
+    .. automethod:: pybricks._common.Control.limits
 
-    .. automethod:: pybricks.builtins.Control.pid
+    .. automethod:: pybricks._common.Control.pid
 
-    .. automethod:: pybricks.builtins.Control.target_tolerances
+    .. automethod:: pybricks._common.Control.target_tolerances
 
-    .. automethod:: pybricks.builtins.Control.stall_tolerances
+    .. automethod:: pybricks._common.Control.stall_tolerances
diff --git a/doc/api/pupdevices.rst b/doc/api/pupdevices.rst
index 72b7501..50822b5 100644
--- a/doc/api/pupdevices.rst
+++ b/doc/api/pupdevices.rst
@@ -7,17 +7,17 @@
 Motors without Rotation Sensors
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-.. autoclass:: pybricks.builtins.DCMotor
+.. autoclass:: pybricks._common.DCMotor
     :noindex:
     :no-members:
 
-    .. automethod:: pybricks.builtins.DCMotor.dc
+    .. automethod:: pybricks._common.DCMotor.dc
         :noindex:
 
-    .. automethod:: pybricks.builtins.DCMotor.stop
+    .. automethod:: pybricks._common.DCMotor.stop
         :noindex:
 
-    .. automethod:: pybricks.builtins.DCMotor.brake
+    .. automethod:: pybricks._common.DCMotor.brake
         :noindex:
 
 Motors with Rotation Sensors
diff --git a/doc/common/conf.py b/doc/common/conf.py
index 0031b71..40c0b49 100644
--- a/doc/common/conf.py
+++ b/doc/common/conf.py
@@ -34,7 +34,7 @@ sys.path.insert(0, TOP_DIR)
 
 from pybricks.hubs import EV3Brick  # noqa E402
 from pybricks.media.ev3dev import Image  # noqa E402
-from pybricks.builtins import Speaker  # noqa E402
+from pybricks._common import Speaker  # noqa E402
 
 # ON_RTD is whether we are on readthedocs.org
 # this line of code grabbed from docs.readthedocs.org
diff --git a/pybricks/builtins.py b/pybricks/_common.py
similarity index 100%
rename from pybricks/builtins.py
rename to pybricks/_common.py
diff --git a/pybricks/ev3devices.py b/pybricks/ev3devices.py
index a3f7aa9..5b83a36 100644
--- a/pybricks/ev3devices.py
+++ b/pybricks/ev3devices.py
@@ -3,8 +3,8 @@
 
 """LEGO® MINDSTORMS® EV3 motors and sensors."""
 
-from .parameters import Direction
-from .builtins import Motor  # noqa E402
+from .parameters import Direction as _Direction
+from ._common import Motor  # noqa E402
 
 
 class TouchSensor:
@@ -153,7 +153,7 @@ class InfraredSensor:
 class GyroSensor:
     """LEGO® MINDSTORMS® EV3 Gyro Sensor."""
 
-    def __init__(self, port, positive_direction=Direction.CLOCKWISE):
+    def __init__(self, port, positive_direction=_Direction.CLOCKWISE):
         """
 
         Arguments:
diff --git a/pybricks/hubs.py b/pybricks/hubs.py
index e404f3d..ba27612 100644
--- a/pybricks/hubs.py
+++ b/pybricks/hubs.py
@@ -2,26 +2,27 @@
 # Copyright (c) 2018-2020 The Pybricks Authors
 
 """LEGO® Programmable Hubs."""
-from .builtins import Speaker, Battery, ColorLight, KeyPad
-from .media.ev3dev import Image
+from ._common import (Speaker as _Speaker, Battery as _Battery,
+                      ColorLight as _ColorLight, KeyPad as _KeyPad)
+from .media.ev3dev import Image as _Image
 
 
 class EV3Brick:
     """LEGO® MINDSTORMS® EV3 Brick."""
-    screen = Image('_screen_')
-    speaker = Speaker()
-    battery = Battery()
-    light = ColorLight()
-    buttons = KeyPad()
+    screen = _Image('_screen_')
+    speaker = _Speaker()
+    battery = _Battery()
+    light = _ColorLight()
+    buttons = _KeyPad()
 
 
 class MoveHub:
     """LEGO® Powered Up Move Hub."""
-    battery = Battery()
-    light = ColorLight()
+    battery = _Battery()
+    light = _ColorLight()
 
 
 class CityHub:
     """LEGO® Powered Up City Hub."""
-    battery = Battery()
-    light = ColorLight()
+    battery = _Battery()
+    light = _ColorLight()
diff --git a/pybricks/media/ev3dev.py b/pybricks/media/ev3dev.py
index 8e77d39..feb7f0f 100644
--- a/pybricks/media/ev3dev.py
+++ b/pybricks/media/ev3dev.py
@@ -3,7 +3,7 @@
 
 """Images and Sounds for Pybricks on ev3dev."""
 
-from ..parameters import Color
+from ..parameters import Color as _Color
 
 
 class Image:
@@ -57,7 +57,7 @@ class Image:
         """
         pass
 
-    def draw_pixel(self, x, y, color=Color.BLACK):
+    def draw_pixel(self, x, y, color=_Color.BLACK):
         """Draws a single pixel on |this image|.
 
         Arguments:
@@ -67,7 +67,7 @@ class Image:
         """
         pass
 
-    def draw_line(self, x1, y1, x2, y2, width=1, color=Color.BLACK):
+    def draw_line(self, x1, y1, x2, y2, width=1, color=_Color.BLACK):
         """Draws a line on |this image|.
 
         Arguments:
@@ -80,7 +80,7 @@ class Image:
         """
         pass
 
-    def draw_box(self, x1, y1, x2, y2, r=0, fill=False, color=Color.BLACK):
+    def draw_box(self, x1, y1, x2, y2, r=0, fill=False, color=_Color.BLACK):
         """Draws a box on |this image|.
 
         Arguments:
@@ -95,7 +95,7 @@ class Image:
         """
         pass
 
-    def draw_circle(self, x, y, r=0, fill=False, color=Color.BLACK):
+    def draw_circle(self, x, y, r=0, fill=False, color=_Color.BLACK):
         """Draws a circle on |this image|.
 
         Arguments:
@@ -134,7 +134,7 @@ class Image:
                 the ``source`` image is loaded from file.
         """
 
-    def draw_text(self, x, y, text, text_color=Color.BLACK, background_color=None):
+    def draw_text(self, x, y, text, text_color=_Color.BLACK, background_color=None):
         """Draws text on |this image|.
 
         The most recent font set using :meth:`set_font` will be used or
diff --git a/pybricks/nxtdevices.py b/pybricks/nxtdevices.py
index 1515e79..2cc5483 100644
--- a/pybricks/nxtdevices.py
+++ b/pybricks/nxtdevices.py
@@ -4,8 +4,8 @@
 """Use LEGO® MINDSTORMS® NXT motors and sensors with the EV3 brick."""
 
 
-from pybricks.iodevices import AnalogSensor
-from pybricks.builtins import ColorLight
+from .iodevices import AnalogSensor as _AnalogSensor
+from ._common import ColorLight as _ColorLight
 
 
 class TouchSensor:
@@ -65,7 +65,7 @@ class LightSensor:
 class ColorSensor:
     """LEGO® MINDSTORMS® NXT Color Sensor."""
 
-    light = ColorLight()
+    light = _ColorLight()
 
     def __init__(self, port):
         """
@@ -242,7 +242,7 @@ class EnergyMeter:
         pass
 
 
-class VernierAdapter(AnalogSensor):
+class VernierAdapter(_AnalogSensor):
     """LEGO® MINDSTORMS® Education NXT/EV3 Adapter for Vernier Sensors."""
 
     def __init__(self, port, conversion=None):
diff --git a/pybricks/parameters.py b/pybricks/parameters.py
index 01b532e..ade3144 100644
--- a/pybricks/parameters.py
+++ b/pybricks/parameters.py
@@ -3,10 +3,10 @@
 
 """Constant parameters/arguments for the Pybricks API."""
 
-from enum import Enum
+from enum import Enum as _Enum
 
 
-class _PybricksEnumMeta(type(Enum)):
+class _PybricksEnumMeta(type(_Enum)):
     def __dir__(cls):
         yield '__class__'
         yield '__name__'
@@ -14,7 +14,7 @@ class _PybricksEnumMeta(type(Enum)):
             yield member.name
 
 
-class _PybricksEnum(Enum, metaclass=_PybricksEnumMeta):
+class _PybricksEnum(_Enum, metaclass=_PybricksEnumMeta):
     def __dir__(self):
         yield '__class__'
         for member in type(self):
diff --git a/pybricks/pupdevices.py b/pybricks/pupdevices.py
index ca1e088..697b95f 100644
--- a/pybricks/pupdevices.py
+++ b/pybricks/pupdevices.py
@@ -3,10 +3,11 @@
 
 """LEGO® Powered Up motor, sensors, and lights."""
 
-from .builtins import KeyPad, Accelerometer, ColorLight, Motor
+from ._common import (KeyPad as _KeyPad, Accelerometer as _Accelerometer,
+                      ColorLight as _ColorLight, Motor as _Motor)
 
 
-class Motor(Motor):
+class Motor(_Motor):
     """Generic class to control motors with built-in rotation sensors."""
 
     def reset_angle(self, angle=None):
@@ -24,8 +25,8 @@ class Motor(Motor):
 class RemoteControl:
     """LEGO® Powered Up Bluetooth Remote Control/Handset."""
 
-    light = ColorLight()
-    buttons = KeyPad()
+    light = _ColorLight()
+    buttons = _KeyPad()
 
     def __init__(self, device=None, timeout=10000):
         """Connect the handset to the hub.
@@ -41,7 +42,7 @@ class RemoteControl:
         pass
 
 
-class TiltSensor(Accelerometer):
+class TiltSensor(_Accelerometer):
     """LEGO® Powered Up Tilt Sensor."""
 
     def __init__(self, port):
@@ -56,7 +57,7 @@ class TiltSensor(Accelerometer):
 class ColorDistanceSensor:
     """LEGO® Powered Up Color and Distance Sensor."""
 
-    light = ColorLight()
+    light = _ColorLight()
 
     def __init__(self, port):
         """ColorDistanceSensor(port)
diff --git a/pybricks/robotics.py b/pybricks/robotics.py
index 52328c0..11e08ca 100644
--- a/pybricks/robotics.py
+++ b/pybricks/robotics.py
@@ -3,19 +3,19 @@
 
 """Robotics module for the Pybricks API."""
 
-from .builtins import Control
+from ._common import Control as _Control
 
 
 class DriveBase:
     """A robotic vehicle with two powered wheels and an optional support
     wheel or caster."""
 
-    distance_control = Control()
+    distance_control = _Control()
     """The traveled distance and drive speed are controlled by a PID
     controller. You can use this attribute to change its settings.
     See :ref:`control` for an overview of available methods."""
 
-    heading_control = Control()
+    heading_control = _Control()
     """The robot turn angle and turn rate are controlled by a PID
     controller. You can use this attribute to change its settings.
     See :ref:`control` for an overview of available methods."""