diff --git a/src/core/unit.c b/src/core/unit.c
index 90f87a95f5..84e9185e82 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -441,6 +441,9 @@ bool unit_may_gc(Unit *u) {
         if (u->perpetual)
                 return false;
 
+        if (u->in_cgroup_empty_queue)
+                return false;
+
         if (sd_bus_track_count(u->bus_track) > 0)
                 return false;
 
diff --git a/test/units/testsuite-19.cleanup-slice.sh b/test/units/testsuite-19.cleanup-slice.sh
new file mode 100755
index 0000000000..5d63160334
--- /dev/null
+++ b/test/units/testsuite-19.cleanup-slice.sh
@@ -0,0 +1,49 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+set -o pipefail
+
+# shellcheck source=test/units/util.sh
+. "$(dirname "$0")"/util.sh
+
+export SYSTEMD_LOG_LEVEL=debug
+
+# Create service with KillMode=none inside a slice
+cat <<EOF >/run/systemd/system/test19cleanup.service
+[Unit]
+Description=Test 19 cleanup Service
+[Service]
+Slice=test19cleanup.slice
+Type=exec
+ExecStart=sleep infinity
+KillMode=none
+EOF
+cat <<EOF >/run/systemd/system/test19cleanup.slice
+[Unit]
+Description=Test 19 cleanup Slice
+EOF
+
+# Start service
+systemctl start test19cleanup.service
+assert_rc 0 systemd-cgls /test19cleanup.slice
+
+pid=$(systemctl show --property MainPID --value test19cleanup)
+ps "$pid"
+
+# Stop slice
+# The sleep process will not be killed because of KillMode=none
+# Since there is still a process running under it, the /test19cleanup.slice cgroup won't be removed
+systemctl stop test19cleanup.slice
+
+ps "$pid"
+
+# Kill sleep process manually
+kill -s TERM "$pid"
+while kill -0 "$pid" 2>/dev/null; do sleep 0.1; done
+
+timeout 30 bash -c 'while systemd-cgls /test19cleanup.slice/test19cleanup.service >& /dev/null; do sleep .5; done'
+assert_rc 1 systemd-cgls /test19cleanup.slice/test19cleanup.service
+
+# Check that empty cgroup /test19cleanup.slice has been removed
+timeout 30 bash -c 'while systemd-cgls /test19cleanup.slice >& /dev/null; do sleep .5; done'
+assert_rc 1 systemd-cgls /test19cleanup.slice