diff --git a/arch/um/kernel/irq.c b/arch/um/kernel/irq.c
index 36e12f0..e7d1983 100644
--- a/arch/um/kernel/irq.c
+++ b/arch/um/kernel/irq.c
@@ -337,6 +337,7 @@ static struct irq_chip normal_irq_type = {
 	.irq_disable = dummy,
 	.irq_enable = dummy,
 	.irq_ack = dummy,
+	.irq_mask = dummy,
 };
 
 static struct irq_chip SIGVTALRM_irq_type = {