diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 3b8435a347d5..19e4b6bab5b1 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -101,6 +101,16 @@ static void cleanup_netns(struct nstoken *nstoken)
 	SYS_NOFAIL("ip netns del %s", NS_TEST);
 }
 
+static int set_nonblock(int fd)
+{
+	int flags = fcntl(fd, F_GETFL);
+
+	if (flags == -1)
+		return -1;
+
+	return fcntl(fd, flags | O_NONBLOCK);
+}
+
 static int verify_tsk(int map_fd, int client_fd)
 {
 	int err, cfd = client_fd;
@@ -332,6 +342,9 @@ static void run_mptcp_subflow(int cgroup_fd, struct mptcp_subflow *skel)
 	if (!ASSERT_GE(client_fd, 0, "connect to fd"))
 		goto close_server;
 
+	if (set_nonblock(server_fd))
+		goto close_server;
+
 	send_recv_data(server_fd, client_fd, total_bytes, TIMEOUT_TEST);
 
 	ASSERT_OK(ss_search(ADDR_1, "fwmark:0x1"), "ss_search fwmark:0x1");
@@ -418,6 +431,9 @@ static void send_data_and_verify(char *msg, int addr1, int addr2)
 	if (!ASSERT_NEQ(client_fd, -1, "connect_to_fd"))
 		goto close_server;
 
+	if (set_nonblock(server_fd))
+		goto close_server;
+
 	if (clock_gettime(CLOCK_MONOTONIC, &start) < 0)
 		goto close_server;