diff --git a/c/src/lib/libbsp/i386/i386ex/clock/ckinit.c b/c/src/lib/libbsp/i386/i386ex/clock/ckinit.c
index aeecd576b3..7f3d92e6d9 100644
--- a/c/src/lib/libbsp/i386/i386ex/clock/ckinit.c
+++ b/c/src/lib/libbsp/i386/i386ex/clock/ckinit.c
@@ -47,7 +47,7 @@ rtems_device_major_number rtems_clock_minor = 0;
  *  This is the ISR handler.
  */
 
-void Clock_isr(void)
+void Clock_isr(rtems_irq_hdl_param unused)
 {
   /* enable_tracing(); */
   Clock_driver_ticks += 1;