diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 5808edfe3f7be4049c857f0d673bcf992f37a62f..f8e53ac5c17dfb94daf880f735b4053f186813aa 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1872,6 +1872,7 @@ static int sci_request_irq(struct sci_port *port)
 		}
 
 		desc = sci_irq_desc + i;
+		port->irqstr[j] = NULL;
 		if (SCIx_TEIDRI_IRQ_EXISTS(port)) {
 			/*
 			 * ERI and BRI are muxed, just register ERI and