diff --git a/etc/mtree/BSD.tests.dist b/etc/mtree/BSD.tests.dist
--- a/etc/mtree/BSD.tests.dist
+++ b/etc/mtree/BSD.tests.dist
@@ -426,6 +426,8 @@
             atf-sh
             ..
         ..
+        rc
+        ..
         rtld-elf
         ..
         tftpd
diff --git a/libexec/rc/Makefile b/libexec/rc/Makefile
--- a/libexec/rc/Makefile
+++ b/libexec/rc/Makefile
@@ -24,4 +24,7 @@
 
 SUBDIR+=	rc.d
 
+HAS_TESTS=
+SUBDIR.${MK_TESTS}+=	tests
+
 .include <bsd.prog.mk>
diff --git a/libexec/rc/tests/Makefile b/libexec/rc/tests/Makefile
new file mode 100644
--- /dev/null
+++ b/libexec/rc/tests/Makefile
@@ -0,0 +1,3 @@
+ATF_TESTS_SH+=  rc_subr_test
+
+.include <bsd.test.mk>
diff --git a/libexec/rc/tests/rc_subr_test.sh b/libexec/rc/tests/rc_subr_test.sh
new file mode 100644
--- /dev/null
+++ b/libexec/rc/tests/rc_subr_test.sh
@@ -0,0 +1,103 @@
+#
+# Copyright 2022 Mateusz Piotrowski <0mp@FreeBSD.org>
+#
+# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+#
+
+atf_test_case oomprotect_all
+oomprotect_all_head()
+{
+	atf_set "descr" "Verify that \${name}_oomprotect=all protects " \
+		"the command and all its current and future children"
+	atf_set "require.user" "root" # For protect(1).
+}
+
+oomprotect_all_body()
+{
+	__name="$(atf_get ident)"
+	__pidfile="$(mktemp -t "${__name}.pid")"
+	__childpidfile="$(mktemp -t "${__name}.childpid")"
+	__script=$(mktemp -t "${__name}.script")
+
+	cat >> "$__script" <<-'LITERAL'
+	. /etc/rc.subr
+	name="$1"
+	pidfile="$2"
+	_childpidfile="$3"
+	_rc_arg="$4"
+	setvar "${name}_oomprotect" all
+	command="/usr/sbin/daemon"
+	command_args="-P $pidfile -p $_childpidfile -- /bin/sleep 5"
+	run_rc_command "$_rc_arg"
+	LITERAL
+
+	atf_check -s exit:0 -o inline:"Starting ${__name}.\n" -e empty \
+		/bin/sh "$__script" "$__name" "$__pidfile" "$__childpidfile" onestart
+	atf_check -s exit:0 -o match:'^..1..... .......1$' -e empty \
+		ps -p "$(cat "$__pidfile")" -ax -o flags,flags2
+	atf_check -s exit:0 -o match:'^..1..... .......1$' -e empty \
+		ps -p "$(cat "$__childpidfile")" -ax -o flags,flags2
+	atf_check -s exit:0 -o ignore -e empty \
+		/bin/sh "$__script" "$__name" "$__pidfile" "$__childpidfile" onestop
+}
+
+atf_test_case oomprotect_yes
+oomprotect_yes_head()
+{
+	atf_set "descr" "Verify that \${name}_oomprotect=yes protects " \
+		"the command but not its children"
+	atf_set "require.user" "root" # For protect(1).
+}
+
+oomprotect_yes_body()
+{
+	__name="$(atf_get ident)"
+	__pidfile="$(mktemp -t "${__name}.pid")"
+	__script=$(mktemp -t "${__name}.script")
+
+	cat >> "$__script" <<-'LITERAL'
+	. /etc/rc.subr
+	name="$1"
+	pidfile="$2"
+	_rc_arg="$3"
+	setvar "${name}_oomprotect" yes
+	procname="/bin/sleep"
+	command="/usr/sbin/daemon"
+	command_args="-p $pidfile -- $procname 5"
+	run_rc_command "$_rc_arg"
+	LITERAL
+
+	atf_check -s exit:0 -o inline:"Starting ${__name}.\n" -e empty \
+		/bin/sh "$__script" "$__name" "$__pidfile" onestart
+	atf_check -s exit:0 -o match:'^..1..... .......0$' -e empty \
+		ps -p "$(cat "$__pidfile")" -ax -o flags,flags2
+	atf_check -s exit:0 -o ignore -e empty \
+		/bin/sh "$__script" "$__name" "$__pidfile" onestop
+}
+
+atf_init_test_cases()
+{
+	atf_add_test_case oomprotect_all
+	atf_add_test_case oomprotect_yes
+}