diff --git a/source/_integrations/mcp23017.markdown b/source/_integrations/mcp23017.markdown
index 4991a3c7d67..35a241040bb 100644
--- a/source/_integrations/mcp23017.markdown
+++ b/source/_integrations/mcp23017.markdown
@@ -14,6 +14,8 @@ The `mcp23017` integration is the base for all related mcp23017 platforms in Hom
 
 For more details about the MCP23017 I2C I/O port expander you can find its datasheet here: [MCP23017](https://www.microchip.com/wwwproducts/en/MCP23017).
 
+If you are using Hass.io on HassOS you can’t use existing methods to enable the I2C bus on a Raspberry Pi, you will have to [enable the I2C interface in the Hass.io configuration](https://github.com/home-assistant/hassos/blob/dev/Documentation/boards/raspberrypi.md#i2c) using a USB stick. To accomplish that, follow this step by step instructions: [Enable HassOS i2c](https://www.home-assistant.io/hassio/enable_i2c).
+
 ## Binary Sensor
 
 The `mcp23017` binary sensor platform allows you to read sensor values from the I/O pins of your [MCP23017 I2C I/O expander](https://www.adafruit.com/product/732).