diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 338dfe8..31b204b 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1501,6 +1501,7 @@ void __cpuinit per_cpu_trap_init(void)
 			cp0_perfcount_irq = -1;
 	} else {
 		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
+		cp0_compare_irq_shift = cp0_compare_irq;
 		cp0_perfcount_irq = -1;
 	}