diff --git a/klippy/pins.py b/klippy/pins.py
index df2c7514..9d3da5e6 100644
--- a/klippy/pins.py
+++ b/klippy/pins.py
@@ -28,7 +28,7 @@ def beaglebone_pins():
 
 MCU_PINS = {
     "atmega168": port_pins(4), "atmega328": port_pins(4),
-    "atmega644p": port_pins(4), "at90usb1286": port_pins(5),
+    "atmega644p": port_pins(4), "at90usb1286": port_pins(6),
     "atmega1280": port_pins(12), "atmega2560": port_pins(12),
     "sam3x8e": port_pins(4, 32),
     "pru": beaglebone_pins(),