diff --git a/sys/dev/uart/uart_dev_sgisn.c b/sys/dev/uart/uart_dev_sgisn.c
index acec5de6e203..c0651a51e9d8 100644
--- a/sys/dev/uart/uart_dev_sgisn.c
+++ b/sys/dev/uart/uart_dev_sgisn.c
@@ -84,8 +84,11 @@ static void
 sgisn_putc(struct uart_bas *bas, int c)
 {
 	struct ia64_sal_result result;
+	char buf[1];
 
-	result = ia64_sal_entry(SAL_SGISN_PUTC, c, 0, 0, 0, 0, 0, 0);
+	buf[0] = c;
+	result = ia64_sal_entry(SAL_SGISN_TXBUF, (uintptr_t)buf, 1UL, 0, 0, 0,
+	    0, 0);
 }
 
 static int
diff --git a/sys/ia64/include/sal.h b/sys/ia64/include/sal.h
index 1aa80279eb5b..babc877d973b 100644
--- a/sys/ia64/include/sal.h
+++ b/sys/ia64/include/sal.h
@@ -119,6 +119,7 @@ struct sal_ap_wakeup_descriptor {
 #define	SAL_SGISN_PUTC		0x02000021
 #define	SAL_SGISN_GETC		0x02000022
 #define	SAL_SGISN_POLL		0x02000026
+#define	SAL_SGISN_TXBUF		0x02000028
 #define	SAL_SGISN_IOHUB_INFO	0x02000055
 #define	SAL_SGISN_IOBUS_INFO	0x02000056