diff --git a/packaging/aleph-vm/etc/systemd/system/aleph-vm-controller@.service b/packaging/aleph-vm/etc/systemd/system/aleph-vm-controller@.service
index c817aad1e..7bbfc67d8 100644
--- a/packaging/aleph-vm/etc/systemd/system/aleph-vm-controller@.service
+++ b/packaging/aleph-vm/etc/systemd/system/aleph-vm-controller@.service
@@ -11,6 +11,12 @@ WorkingDirectory=/opt/aleph-vm
 Environment=PYTHONPATH=/opt/aleph-vm/:$PYTHONPATH
 ExecStart=/usr/bin/python3 -m aleph.vm.controllers --config=/var/lib/aleph/vm/%i-controller.json
 Restart=on-failure
+# KillMode=Mixed is used so initially only the Python controller process receives the SIGTERM signal.
+# The controller catches it and sends a QEMU command to shut down the Guest VM, allowing it to clean up
+# properly and avoid disk corruption.
+# After 30s (TimeoutStopSec), if the process is still running, both the controller and subprocesses receive SIGKILL.
+KillMode=mixed
+TimeoutStopSec=30
 
 [Install]
 WantedBy=multi-user.target
diff --git a/src/aleph/vm/controllers/__main__.py b/src/aleph/vm/controllers/__main__.py
index 19701c4bf..519270b48 100644
--- a/src/aleph/vm/controllers/__main__.py
+++ b/src/aleph/vm/controllers/__main__.py
@@ -90,6 +90,7 @@ async def handle_persistent_vm(config: Configuration, execution: MicroVM | QemuV
 
     def callback():
         """Callback for the signal handler to stop the VM and cleanup properly on SIGTERM."""
+        logger.debug("Received SIGTERM")
         loop.create_task(execution.stop())
 
     loop.add_signal_handler(signal.SIGTERM, callback)