diff --git a/tools/testing/selftests/net/cmsg_sender.c b/tools/testing/selftests/net/cmsg_sender.c
index 24b21b15ed3f..6ff3e732f449 100644
--- a/tools/testing/selftests/net/cmsg_sender.c
+++ b/tools/testing/selftests/net/cmsg_sender.c
@@ -416,9 +416,9 @@ int main(int argc, char *argv[])
 {
 	struct addrinfo hints, *ai;
 	struct iovec iov[1];
+	unsigned char *buf;
 	struct msghdr msg;
 	char cbuf[1024];
-	char *buf;
 	int err;
 	int fd;