diff --git a/extensions/slack/src/monitor/auth.ts b/extensions/slack/src/monitor/auth.ts
index f243513fa038..4b032338551f 100644
--- a/extensions/slack/src/monitor/auth.ts
+++ b/extensions/slack/src/monitor/auth.ts
@@ -14,6 +14,7 @@ import {
   resolveExpiresAtMsFromDurationMs,
 } from "openclaw/plugin-sdk/number-runtime";
 import { logVerbose } from "openclaw/plugin-sdk/runtime-env";
+import { normalizeOptionalLowercaseString } from "openclaw/plugin-sdk/string-coerce-runtime";
 import { collectSlackCursorPages } from "../cursor-pages.js";
 import { parseSlackTarget } from "../target-parsing.js";
 import {