diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 01d4a0de061f5a5c1b1aaf7c3ce3e8274ba5a24c..92e06442d74c00247927952c1fe6e8423bf7369b 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -758,8 +758,8 @@ static int __init irq_debugfs_init(void)
 __initcall(irq_debugfs_init);
 #endif /* CONFIG_IRQ_DOMAIN_DEBUG */
 
-int irq_domain_simple_map(struct irq_domain *d, unsigned int irq,
-			  irq_hw_number_t hwirq)
+static int irq_domain_simple_map(struct irq_domain *d, unsigned int irq,
+				 irq_hw_number_t hwirq)
 {
 	return 0;
 }