diff --git a/xen/arch/arm/include/asm/irq.h b/xen/arch/arm/include/asm/irq.h
index af94f41994..11bc85d111 100644
--- a/xen/arch/arm/include/asm/irq.h
+++ b/xen/arch/arm/include/asm/irq.h
@@ -89,7 +89,7 @@ int irq_set_type(unsigned int irq, unsigned int type);
 
 int platform_get_irq(const struct dt_device_node *device, int index);
 
-int platform_get_irq_byname(struct dt_device_node *np, const char *name);
+int platform_get_irq_byname(const struct dt_device_node *np, const char *name);
 
 void irq_set_affinity(struct irq_desc *desc, const cpumask_t *cpu_mask);
 
diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index ded495792b..16e56f8945 100644
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -718,7 +718,7 @@ int platform_get_irq(const struct dt_device_node *device, int index)
     return irq;
 }
 
-int platform_get_irq_byname(struct dt_device_node *np, const char *name)
+int platform_get_irq_byname(const struct dt_device_node *np, const char *name)
 {
 	int index;