diff --git a/docs/modules/am2320.md b/docs/modules/am2320.md
index 1f8c544b..5b099455 100644
--- a/docs/modules/am2320.md
+++ b/docs/modules/am2320.md
@@ -6,6 +6,10 @@
 
 This module provides access to the [AM2320](https://akizukidenshi.com/download/ds/aosong/AM2320.pdf) humidity and temperature sensor, using the i2c interface.
 
+!!! caution
+
+    This code is licensed under GPL by its author. Any binaries that include this module becomes subject to the GPL, requiring anyone who ships them to also ship source.
+
 ## am2320.read()
 Samples the sensor and returns the relative humidity in % and temperature in celsius, as an integer multiplied with 10.