diff --git a/arch/powerpc/kernel/ibmebus.c b/arch/powerpc/kernel/ibmebus.c
index 64299d28f364..7c6537777b2c 100644
--- a/arch/powerpc/kernel/ibmebus.c
+++ b/arch/powerpc/kernel/ibmebus.c
@@ -231,6 +231,7 @@ void ibmebus_free_irq(u32 ist, void *dev_id)
 	unsigned int irq = irq_find_mapping(NULL, ist);
 
 	free_irq(irq, dev_id);
+	irq_dispose_mapping(irq);
 }
 EXPORT_SYMBOL(ibmebus_free_irq);