diff --git a/delete.go b/delete.go
index 682101cca..e8b92ae5a 100644
--- a/delete.go
+++ b/delete.go
@@ -66,6 +66,14 @@ status of "ubuntu01" as "stopped" the following will delete resources held for
 			}
 			return err
 		}
+		// When --force is given, we kill all container processes and
+		// then destroy the container. This is done even for a stopped
+		// container, because (in case it does not have its own PID
+		// namespace) there may be some leftover processes in the
+		// container's cgroup.
+		if force {
+			return killContainer(container)
+		}
 		s, err := container.Status()
 		if err != nil {
 			return err
@@ -76,9 +84,6 @@ status of "ubuntu01" as "stopped" the following will delete resources held for
 		case libcontainer.Created:
 			return killContainer(container)
 		default:
-			if force {
-				return killContainer(container)
-			}
 			return fmt.Errorf("cannot delete container %s that is not stopped: %s", id, s)
 		}
 
diff --git a/tests/integration/delete.bats b/tests/integration/delete.bats
index e9b80b64d..8cc53c19e 100644
--- a/tests/integration/delete.bats
+++ b/tests/integration/delete.bats
@@ -62,6 +62,69 @@ function teardown() {
 	[ "$status" -eq 0 ]
 }
 
+# Issue 4047, case "runc delete -f".
+# See also: "kill KILL [host pidns + init gone]" test in kill.bats.
+@test "runc delete --force [host pidns + init gone]" {
+	requires cgroups_freezer
+
+	update_config '	  .linux.namespaces -= [{"type": "pid"}]'
+	set_cgroups_path
+	if [ $EUID -ne 0 ]; then
+		requires rootless_cgroup
+		# Apparently, for rootless test, when using systemd cgroup manager,
+		# newer versions of systemd clean up the container as soon as its init
+		# process is gone. This is all fine and dandy, except it prevents us to
+		# test this case, thus we skip the test.
+		#
+		# It is not entirely clear which systemd version got this feature:
+		# v245 works fine, and v249 does not.
+		if [ -v RUNC_USE_SYSTEMD ] && [ "$(systemd_version)" -gt 245 ]; then
+			skip "rootless+systemd conflicts with systemd > 245"
+		fi
+		# Can't mount real /proc when rootless + no pidns,
+		# so change it to a bind-mounted one from the host.
+		update_config '	  .mounts |= map((select(.type == "proc")
+					| .type = "none"
+					| .source = "/proc"
+					| .options = ["rbind", "nosuid", "nodev", "noexec"]
+				  ) // .)'
+	fi
+
+	runc run -d --console-socket "$CONSOLE_SOCKET" test_busybox
+	[ "$status" -eq 0 ]
+	cgpath=$(get_cgroup_path "pids")
+	init_pid=$(cat "$cgpath"/cgroup.procs)
+
+	# Start a few more processes.
+	for _ in 1 2 3 4 5; do
+		__runc exec -d test_busybox sleep 1h
+	done
+
+	# Now kill the container's init process. Since the container do
+	# not have own PID ns, its init is no special and the container
+	# will still be up and running.
+	kill -9 "$init_pid"
+
+	# Get the list of all container processes.
+	pids=$(cat "$cgpath"/cgroup.procs)
+	echo "pids: $pids"
+	# Sanity check -- make sure all processes exist.
+	for p in $pids; do
+		kill -0 "$p"
+	done
+
+	runc delete -f test_busybox
+	[ "$status" -eq 0 ]
+
+	runc state test_busybox
+	[ "$status" -ne 0 ] # "Container does not exist"
+
+	# Make sure all processes are gone.
+	pids=$(cat "$cgpath"/cgroup.procs) || true # OK if cgroup is gone
+	echo "pids: $pids"
+	[ -z "$pids" ]
+}
+
 @test "runc delete --force [paused container]" {
 	runc run -d --console-socket "$CONSOLE_SOCKET" ct1
 	[ "$status" -eq 0 ]
diff --git a/tests/integration/kill.bats b/tests/integration/kill.bats
index ad116df0d..3124bb0e5 100644
--- a/tests/integration/kill.bats
+++ b/tests/integration/kill.bats
@@ -109,6 +109,7 @@ test_host_pidns_kill() {
 # 3. Test runc kill on a container whose init process is gone.
 #
 # Issue 4047, case "runc kill".
+# See also: "runc delete --force [host pidns + init gone]" test in delete.bats.
 @test "kill KILL [host pidns + init gone]" {
 	# Apparently, for rootless test, when using systemd cgroup manager,
 	# newer versions of systemd clean up the container as soon as its init