diff --git a/tools/net/ynl/lib/ynl-priv.h b/tools/net/ynl/lib/ynl-priv.h
index 824777d7e05e..fca519d7ec9a 100644
--- a/tools/net/ynl/lib/ynl-priv.h
+++ b/tools/net/ynl/lib/ynl-priv.h
@@ -314,7 +314,7 @@ ynl_attr_put_str(struct nlmsghdr *nlh, unsigned int attr_type, const char *str)
 	struct nlattr *attr;
 	size_t len;
 
-	len = strlen(str);
+	len = strlen(str) + 1;
 	if (__ynl_attr_put_overflow(nlh, len))
 		return;
 
@@ -322,7 +322,7 @@ ynl_attr_put_str(struct nlmsghdr *nlh, unsigned int attr_type, const char *str)
 	attr->nla_type = attr_type;
 
 	strcpy((char *)ynl_attr_data(attr), str);
-	attr->nla_len = NLA_HDRLEN + NLA_ALIGN(len);
+	attr->nla_len = NLA_HDRLEN + len;
 
 	nlh->nlmsg_len += NLMSG_ALIGN(attr->nla_len);
 }