diff --git a/README.md b/README.md
index 3180ee2..3439b4e 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,7 @@ The following peripherals are currently supported:
 
 * GPIO (without PWM).
 * SPI.
+* I2C (SMBUS).
 
 ## Requirements
 
diff --git a/docs/src/index.md b/docs/src/index.md
index 4651bae..7ca469e 100644
--- a/docs/src/index.md
+++ b/docs/src/index.md
@@ -14,8 +14,9 @@ Raspberry Pi W Zero. Help is needed to improve the reliability of the package.
 
 The following peripherals are currently supported:
 
-* GPIO.
+* GPIO (without PWM).
 * SPI.
+* I2C (SMBUS).
 
 ## Requirements