diff --git a/examples/basic.py b/examples/basic.py
index 5135745..bb7cb4b 100644
--- a/examples/basic.py
+++ b/examples/basic.py
@@ -1,6 +1,6 @@
 from WelcomeScreen import WelcomeScreen
-from machine import I2C, Pin
-from PCF8574T import I2C_LCD
+from machine import I2C, Pin  # micropython's built-in library
+from PCF8574T import I2C_LCD  # https://git.privacynerd.de/BlueFox/micropython-libraries/src/branch/main/PCF8574T
 
 LCD_SDA = Pin(8)                              # just some standard I2C serial data (SDA) outputs (on I2C channel 0 on Pi Pico)
 LCD_SCL = Pin(9)                              # just some standard I2C serial clock (SCL) outputs (on I2C channel 0 on Pi Pico)