diff --git a/examples/fingerprint_simpletest.py b/examples/fingerprint_simpletest.py
index d1fe831..9b597b3 100644
--- a/examples/fingerprint_simpletest.py
+++ b/examples/fingerprint_simpletest.py
@@ -9,10 +9,14 @@
 
 uart = busio.UART(board.TX, board.RX, baudrate=57600)
 
-# If using with a computer such as Linux/RaspberryPi, Mac, Windows...
+# If using with a computer such as Linux/RaspberryPi, Mac, Windows with USB/serial converter:
 #import serial
 #uart = serial.Serial("/dev/ttyUSB0", baudrate=57600, timeout=1)
 
+# If using with Linux/Raspberry Pi and hardware UART:
+#import serial
+#uart = serial.Serial("/dev/ttyS0", baudrate=57600, timeout=1)
+
 finger = adafruit_fingerprint.Adafruit_Fingerprint(uart)
 
 ##################################################
diff --git a/requirements.txt b/requirements.txt
index edf9394..bf1f946 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1 +1,2 @@
 Adafruit-Blinka
+pyserial
\ No newline at end of file
diff --git a/setup.py b/setup.py
index bc3492e..9bccdab 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',