diff --git a/hw/arm/allwinner-a10.c b/hw/arm/allwinner-a10.c
index 05e84728cb..79082289ea 100644
--- a/hw/arm/allwinner-a10.c
+++ b/hw/arm/allwinner-a10.c
@@ -130,9 +130,7 @@ static void aw_a10_realize(DeviceState *dev, Error **errp)
         int i;
 
         for (i = 0; i < AW_A10_NUM_USB; i++) {
-            char bus[16];
-
-            sprintf(bus, "usb-bus.%d", i);
+            g_autofree char *bus = g_strdup_printf("usb-bus.%d", i);
 
             object_property_set_bool(OBJECT(&s->ehci[i]), "companion-enable",
                                      true, &error_fatal);