diff --git a/instances/templates/instances/snapshots_tab.html b/instances/templates/instances/snapshots_tab.html
index 9700b592..2060653c 100755
--- a/instances/templates/instances/snapshots_tab.html
+++ b/instances/templates/instances/snapshots_tab.html
@@ -147,7 +147,7 @@
                                             {% csrf_token %}
                                             <input type="hidden" name="name" value="{{ ext_snap.name }}">
                                             <button type="submit" class="btn btn-sm btn-primary" name="revert_external_snapshot" title="{% trans 'Revert to this Snapshot' %}"
-                                                    data-confirm="{% trans 'Revert to this snapshot? Changes made since it are lost.' %}{% if ext_snap.detaches %} {% trans 'These disks are detached; their writes since the current snapshot are discarded and their files are kept:' %} {% for d in ext_snap.detaches %}{{ d.dev }} ({{ d.path }}){% if not forloop.last %}, {% endif %}{% endfor %}.{% endif %}{% if instance.nvram %} {% trans 'Firmware variables (NVRAM) are not restored.' %}{% endif %}"
+                                                    data-confirm="{% trans 'Revert to this snapshot? Changes made since it are lost.' %}{% if not ext_snap.memory %}{% if instance.status == 1 or instance.status == 3 %} {% trans "The VM is powered off and starts again from the snapshot's disks, as after a power cut." %}{% endif %}{% endif %}{% if ext_snap.detaches %} {% trans 'These disks are detached; their writes since the current snapshot are discarded and their files are kept:' %} {% for d in ext_snap.detaches %}{{ d.dev }} ({{ d.path }}){% if not forloop.last %}, {% endif %}{% endfor %}.{% endif %}{% if instance.nvram %} {% trans 'Firmware variables (NVRAM) are not restored.' %}{% endif %}"
                                                     onclick="return confirm(this.dataset.confirm)" {% if busy %}disabled{% endif %}>
                                                 <span>{% bs_icon 'download' %} </span>
                                             </button>
diff --git a/instances/tests/test_snapshot_views.py b/instances/tests/test_snapshot_views.py
index 55b2fac7..8e3521da 100644
--- a/instances/tests/test_snapshot_views.py
+++ b/instances/tests/test_snapshot_views.py
@@ -137,6 +137,13 @@ class SnapshotTabTestCase(TestCase):
         doc = self.page(external=[self.snap("e")], jobs=libvirt.libvirtError("no job info"))
         self.assertEqual(len(doc.xpath("//button[@name='revert_external_snapshot']")), 1)
 
+    def test_revert_confirm_says_a_disk_only_revert_restarts_the_guest(self):
+        for status, memory, restarts in ((1, False, True), (3, False, True), (5, False, False), (1, True, False)):
+            with self.subTest(status=status, memory=memory):
+                doc = self.page(external=[self.snap("e", memory=memory)], status=status)
+                [button] = doc.xpath("//button[@name='revert_external_snapshot']")
+                self.assertEqual("powered off" in button.get("data-confirm"), restarts)
+
     def test_memory_checkbox_only_for_a_running_vm(self):
         self.assertFalse(self.page(status=1).xpath("//input[@name='memory']")[0].get("disabled"))
         self.assertIsNotNone(self.page(status=5).xpath("//input[@name='memory']")[0].get("disabled"))