diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index bf0b40b0fad4..61949c1ce40a 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -198,6 +198,9 @@ static struct irq_chip plic_edge_chip = {
 #endif
 	.irq_set_type	= plic_irq_set_type,
 	.flags		= IRQCHIP_SKIP_SET_WAKE |
+#ifdef CONFIG_PREEMPT_RT
+			  IRQCHIP_EOI_THREADED |
+#endif
 			  IRQCHIP_AFFINITY_PRE_STARTUP,
 };
 
@@ -213,6 +216,9 @@ static struct irq_chip plic_chip = {
 #endif
 	.irq_set_type	= plic_irq_set_type,
 	.flags		= IRQCHIP_SKIP_SET_WAKE |
+#ifdef CONFIG_PREEMPT_RT
+			  IRQCHIP_EOI_THREADED |
+#endif
 			  IRQCHIP_AFFINITY_PRE_STARTUP,
 };