diff --git a/tests/sys/kern/Makefile b/tests/sys/kern/Makefile
index f2fe9e7008d..6396b22005c 100644
--- a/tests/sys/kern/Makefile
+++ b/tests/sys/kern/Makefile
@@ -48,6 +48,7 @@ TEST_METADATA.unix_seqpacket_test+=	timeout="15"
 ATF_TESTS_C+=	unix_socketpair_test
 ATF_TESTS_C+=	waitpid_nohang
 ATF_TESTS_C+=	pdeathsig
+ATF_TESTS_C+=	sigsys
 
 ATF_TESTS_SH+=	coredump_phnum_test
 ATF_TESTS_SH+=	sonewconn_overflow
diff --git a/tests/sys/kern/sigsys.c b/tests/sys/kern/sigsys.c
new file mode 100644
index 00000000000..75e3816fc15
--- /dev/null
+++ b/tests/sys/kern/sigsys.c
@@ -0,0 +1,69 @@
+/*-
+ * Copyright (c) 2023 The FreeBSD Foundation
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * This software were developed by Konstantin Belousov <kib@FreeBSD.org>
+ * under sponsorship from the FreeBSD Foundation.
+ */
+
+#include <sys/syscall.h>
+
+#include <atf-c.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdatomic.h>
+#include <stdbool.h>
+
+static sig_atomic_t sigsys_cnt;
+
+static void
+sigsys_handler(int signo, siginfo_t *si, void *ucp)
+{
+	sigsys_cnt++;
+}
+
+ATF_TC(sigsys_test);
+
+ATF_TC_HEAD(sigsys_test, tc)
+{
+	atf_tc_set_md_var(tc, "descr",
+	    "Testing delivery of SIGSYS on invalid syscalls");
+}
+
+ATF_TC_BODY(sigsys_test, tc)
+{
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.sa_sigaction = sigsys_handler;
+	sa.sa_flags = SA_SIGINFO;
+	ATF_REQUIRE(sigaction(SIGSYS, &sa, NULL) == 0);
+
+	ATF_REQUIRE(syscall(273) == -1);	/* reserved */
+	ATF_CHECK_ERRNO(ENOSYS, true);
+	atomic_signal_fence(memory_order_seq_cst);
+	ATF_CHECK_EQ(1, sigsys_cnt);
+
+	ATF_REQUIRE(syscall(440) == -1);	/* SYS_kse_switchin */
+	ATF_CHECK_ERRNO(ENOSYS, true);
+	atomic_signal_fence(memory_order_seq_cst);
+	ATF_CHECK_EQ(2, sigsys_cnt);
+
+	/* Hope this is enough for say next two months */
+	ATF_REQUIRE(syscall(3000000) == -1);
+	ATF_CHECK_ERRNO(ENOSYS, true);
+	atomic_signal_fence(memory_order_seq_cst);
+	ATF_CHECK_EQ(3, sigsys_cnt);
+
+	ATF_REQUIRE(syscall(SYS_afs3_syscall) == -1);
+	ATF_CHECK_ERRNO(ENOSYS, true);
+	atomic_signal_fence(memory_order_seq_cst);
+	ATF_CHECK_EQ(4, sigsys_cnt);
+}
+
+ATF_TP_ADD_TCS(tp)
+{
+	ATF_TP_ADD_TC(tp, sigsys_test);
+	return (atf_no_error());
+}