diff --git a/README.md b/README.md
index 247f40f..b0f5beb 100644
--- a/README.md
+++ b/README.md
@@ -38,7 +38,7 @@ You have to short-circuit `R0` on the RS485 boards to enable the termination res
 | GPIO | Usage          |
 | ---- | -------------- |
 | GND  | GND to others  |
-| 3,5V | VIN on RS485   |
+| 3,3V | VIN on RS485   |
 | 3,3V | VIN on W5500   |
 | 0    | Onboard Button |
 | 5    | Ext. Button    |