diff --git a/cpu/cc2538/usb/usb-arch.c b/cpu/cc2538/usb/usb-arch.c
index d9c58558b..c209d7778 100644
--- a/cpu/cc2538/usb/usb-arch.c
+++ b/cpu/cc2538/usb/usb-arch.c
@@ -54,8 +54,12 @@
 #include <stdbool.h>
 #include <stdint.h>
 /*---------------------------------------------------------------------------*/
+#ifdef USB_PULLUP_PORT
 #define USB_PULLUP_PORT_BASE     GPIO_PORT_TO_BASE(USB_PULLUP_PORT)
+#endif
+#ifdef USB_PULLUP_PIN
 #define USB_PULLUP_PIN_MASK      GPIO_PIN_MASK(USB_PULLUP_PIN)
+#endif
 /*---------------------------------------------------------------------------*/
 /* EP max FIFO sizes without double buffering */
 #if CTRL_EP_SIZE > 32
@@ -332,9 +336,11 @@ usb_arch_setup(void)
   /* Wait until USB PLL is stable */
   while(!(REG(USB_CTRL) & USB_CTRL_PLL_LOCKED));
 
-  /* Enable pull-up on usb port */
+  /* Enable pull-up on usb port if driven by GPIO */
+#if defined(USB_PULLUP_PORT_BASE) && defined(USB_PULLUP_PIN_MASK)
   GPIO_SET_OUTPUT(USB_PULLUP_PORT_BASE, USB_PULLUP_PIN_MASK);
   GPIO_SET_PIN(USB_PULLUP_PORT_BASE, USB_PULLUP_PIN_MASK);
+#endif
 
   for(i = 0; i < USB_MAX_ENDPOINTS; i++) {
     usb_endpoints[i].flags = 0;