diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 210a5795963772..d6515bf764442b 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -293,7 +293,7 @@ static void plic_irq_resume(void *data)
 			continue;
 
 		raw_spin_lock_irqsave(&handler->enable_lock, flags);
-		for (i = 0; i < DIV_ROUND_UP(priv->nr_irqs, 32); i++) {
+		for (i = 0; i < DIV_ROUND_UP(priv->nr_irqs + 1, 32); i++) {
 			reg = handler->enable_base + i * sizeof(u32);
 			writel(handler->enable_save[i], reg);
 		}
@@ -431,7 +431,7 @@ static u32 cp100_isolate_pending_irq(int nr_irq_groups, struct plic_handler *han
 
 static irq_hw_number_t cp100_get_hwirq(struct plic_handler *handler, void __iomem *claim)
 {
-	int nr_irq_groups = DIV_ROUND_UP(handler->priv->nr_irqs, 32);
+	int nr_irq_groups = DIV_ROUND_UP(handler->priv->nr_irqs + 1, 32);
 	u32 __iomem *enable = handler->enable_base;
 	irq_hw_number_t hwirq = 0;
 	u32 iso_mask;
@@ -718,7 +718,7 @@ static int plic_probe(struct fwnode_handle *fwnode)
 			context_id * CONTEXT_ENABLE_SIZE;
 		handler->priv = priv;
 
-		handler->enable_save = kcalloc(DIV_ROUND_UP(nr_irqs, 32),
+		handler->enable_save = kcalloc(DIV_ROUND_UP(nr_irqs + 1, 32),
 					       sizeof(*handler->enable_save), GFP_KERNEL);
 		if (!handler->enable_save) {
 			error = -ENOMEM;