diff --git a/setup.py b/setup.py
index cb41879..2f4c39e 100644
--- a/setup.py
+++ b/setup.py
@@ -34,7 +34,7 @@
     author='Adafruit Industries',
     author_email='circuitpython@adafruit.com',
 
-    install_requires=['Adafruit-Blinka'],
+    install_requires=['Adafruit-Blinka', 'pyserial'],
 
     # Choose your license
     license='MIT',