diff --git a/server/migrations/131_issue_origin_slack_chat.down.sql b/server/migrations/131_issue_origin_slack_chat.down.sql
new file mode 100644
index 000000000..52a45cbe3
--- /dev/null
+++ b/server/migrations/131_issue_origin_slack_chat.down.sql
@@ -0,0 +1,8 @@
+-- Revert to the pre-slack_chat issue_origin_type_check list. Any existing rows
+-- with origin_type='slack_chat' would violate the rolled-back constraint; the
+-- down migration assumes the operator has already deleted or relabeled those
+-- rows. Kept strict (no DROP NOT VALID dance) to preserve the schema invariant
+-- downstream code relies on. Mirrors 111.
+ALTER TABLE issue DROP CONSTRAINT IF EXISTS issue_origin_type_check;
+ALTER TABLE issue ADD CONSTRAINT issue_origin_type_check
+    CHECK (origin_type IN ('autopilot', 'quick_create', 'lark_chat'));
diff --git a/server/migrations/131_issue_origin_slack_chat.up.sql b/server/migrations/131_issue_origin_slack_chat.up.sql
new file mode 100644
index 000000000..bc22c5791
--- /dev/null
+++ b/server/migrations/131_issue_origin_slack_chat.up.sql
@@ -0,0 +1,10 @@
+-- Extend issue.origin_type to allow the Slack `/issue` command paths (both the
+-- message-prefix form and the slash command) to stamp issues with
+-- origin_type='slack_chat'. The Slack integration shipped this origin label
+-- (originSlackChat) but no migration ever added it to the CHECK list, so every
+-- Slack /issue create tripped SQLSTATE 23514 and IssueService.Create failed —
+-- surfaced end-to-end by the /issue slash command (MUL-3908). Mirrors 111
+-- (lark_chat), which fixed the identical gap for Lark.
+ALTER TABLE issue DROP CONSTRAINT IF EXISTS issue_origin_type_check;
+ALTER TABLE issue ADD CONSTRAINT issue_origin_type_check
+    CHECK (origin_type IN ('autopilot', 'quick_create', 'lark_chat', 'slack_chat'));