diff --git a/drivers/thunderbolt/xdomain.c b/drivers/thunderbolt/xdomain.c
index d66ea4d616fd..eff32499610f 100644
--- a/drivers/thunderbolt/xdomain.c
+++ b/drivers/thunderbolt/xdomain.c
@@ -730,7 +730,7 @@ static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 
 	/* Full buffer size except new line and null termination */
 	get_modalias(svc, buf, PAGE_SIZE - 2);
-	return sprintf(buf, "%s\n", buf);
+	return strlen(strcat(buf, "\n"));
 }
 static DEVICE_ATTR_RO(modalias);