diff --git a/arch/x86/kernel/time_32.c b/arch/x86/kernel/time_32.c
index 7215bc6..77b400f 100644
--- a/arch/x86/kernel/time_32.c
+++ b/arch/x86/kernel/time_32.c
@@ -94,6 +94,7 @@
 
 	do_timer_interrupt_hook();
 
+#ifdef CONFIG_MCA
 	if (MCA_bus) {
 		/* The PS/2 uses level-triggered interrupts.  You can't
 		turn them off, nor would you want to (any attempt to
@@ -107,6 +108,7 @@
 		u8 irq_v = inb_p( 0x61 );	/* read the current state */
 		outb_p( irq_v|0x80, 0x61 );	/* reset the IRQ */
 	}
+#endif
 
 	return IRQ_HANDLED;
 }
diff --git a/arch/x86/kernel/time_64.c b/arch/x86/kernel/time_64.c
index 2be67c2..207a7a1 100644
--- a/arch/x86/kernel/time_64.c
+++ b/arch/x86/kernel/time_64.c
@@ -16,6 +16,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/time.h>
+#include <linux/mca.h>
 
 #include <asm/i8253.h>
 #include <asm/hpet.h>
@@ -54,6 +55,13 @@
 
 	global_clock_event->event_handler(global_clock_event);
 
+#ifdef CONFIG_MCA
+	if (MCA_bus) {
+		u8 irq_v = inb_p(0x61);       /* read the current state */
+		outb_p(irq_v|0x80, 0x61);     /* reset the IRQ */
+	}
+#endif
+
 	return IRQ_HANDLED;
 }