diff --git a/firmware/ice40-riscv/icE1usb/e1.h b/firmware/ice40-riscv/icE1usb/e1.h
index 9ceffdd..862d568 100644
--- a/firmware/ice40-riscv/icE1usb/e1.h
+++ b/firmware/ice40-riscv/icE1usb/e1.h
@@ -57,5 +57,5 @@
 	E1P_LED_ST_BLINK_FAST	= 3
 };
 
-extern void e1_platform_led_set(uint8_t port, enum e1_platform_led led,
+extern void e1_platform_led_set(int port, enum e1_platform_led led,
 				enum e1_platform_led_state state);