diff --git a/src/generic/armcm_timer.h b/src/generic/armcm_timer.h
deleted file mode 100644
index 6d6f5ac..0000000
--- a/src/generic/armcm_timer.h
+++ /dev/null
@@ -1,8 +0,0 @@
-#ifndef __GENERIC_ARMCM_TIMER_H
-#define __GENERIC_ARMCM_TIMER_H
-
-#include <stdint.h> // uint32_t
-
-void udelay(uint32_t usecs);
-
-#endif // armcm_timer.h
diff --git a/src/stm32/usbfs.c b/src/stm32/usbfs.c
index 1302d52..77f74f2 100644
--- a/src/stm32/usbfs.c
+++ b/src/stm32/usbfs.c
@@ -6,7 +6,6 @@
 
 #include <string.h> // NULL
 #include "board/armcm_boot.h" // armcm_enable_irq
-#include "board/armcm_timer.h" // udelay
 #include "board/gpio.h" // gpio_out_setup
 #include "board/io.h" // writeb
 #include "board/usb_cdc.h" // usb_notify_ep0