diff --git a/openupgrade_scripts/scripts/im_livechat/19.0.1.0/post-migration.py b/openupgrade_scripts/scripts/im_livechat/19.0.1.0/post-migration.py
index 5aa89d143a0..03591793d5f 100644
--- a/openupgrade_scripts/scripts/im_livechat/19.0.1.0/post-migration.py
+++ b/openupgrade_scripts/scripts/im_livechat/19.0.1.0/post-migration.py
@@ -30,6 +30,27 @@ def im_livechat_channel_rule_chatbot_enabled_condition(env):
     )
 
 
+def discuss_channel_livechat_end_dt(env):
+    """19.0 replaces the ``livechat_active`` boolean with ``livechat_end_dt``.
+    Without a backfill every historically closed session migrates as still
+    open (multi-year durations, live status in the new dashboards). Clearing
+    the status also satisfies CHECK(livechat_end_dt IS NULL OR livechat_status
+    IS NULL)."""
+    if not openupgrade.column_exists(env.cr, "discuss_channel", "livechat_active"):
+        return
+    openupgrade.logged_query(
+        env.cr,
+        """
+        UPDATE discuss_channel
+        SET livechat_end_dt = COALESCE(write_date, create_date),
+            livechat_status = NULL
+        WHERE channel_type = 'livechat'
+          AND livechat_active IS NOT TRUE
+          AND livechat_end_dt IS NULL
+        """,
+    )
+
+
 @openupgrade.migrate()
 def migrate(env, version):
     openupgrade.load_data(env, "im_livechat", "19.0.1.0/noupdate_changes.xml")
@@ -43,3 +64,4 @@ def migrate(env, version):
     )
     chatbot_script_step_message(env)
     im_livechat_channel_rule_chatbot_enabled_condition(env)
+    discuss_channel_livechat_end_dt(env)