diff --git a/requirements.txt b/requirements.txt
index 3031961..929bb64 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,3 @@
 Adafruit-Blinka
 adafruit-circuitpython-busdevice
+pyserial
diff --git a/setup.py b/setup.py
index cdcd96a..4d0971d 100644
--- a/setup.py
+++ b/setup.py
@@ -34,7 +34,7 @@
     author='Adafruit Industries',
     author_email='circuitpython@adafruit.com',
 
-    install_requires=['Adafruit-Blinka', 'adafruit-circuitpython-busdevice'],
+    install_requires=['Adafruit-Blinka', 'adafruit-circuitpython-busdevice', 'pyserial'],
 
     # Choose your license
     license='MIT',