diff --git a/src/keeper.ts b/src/keeper.ts
index f97252c..540d6aa 100644
--- a/src/keeper.ts
+++ b/src/keeper.ts
@@ -5,8 +5,8 @@
  * real-user-wins semantics, plus the idle-watch loop that drives it.
  *
  * Runtime: Bun (uses `@nut-tree-fork/nut-js` for cross-platform mouse +
- * screen). Importing this module sets `mouse.config.autoDelayMs = 0` as a
- * side effect — see below.
+ * screen). The nut.js auto-delay is disabled inside `runKeeper`, not at
+ * module load, so importing this module is side-effect-free.
  *
  * Logging policy:
  *  - The startup banner in `runKeeper` is unconditional so the user always
@@ -20,14 +20,6 @@ import { mouse, Point, screen } from "@nut-tree-fork/nut-js";
 
 import type { Config } from "./config.ts";
 
-/**
- * nut.js inserts a configurable delay after every action (default 100ms).
- * That default would silently more-than-double the duration of every
- * `setPosition` and `getPosition` call. We drive cadence ourselves via
- * `Config.stepDelay`, so disable nut.js's implicit delay entirely.
- */
-mouse.config.autoDelayMs = 0;
-
 /**
  * Promise-based `setTimeout` wrapper. Allows `await sleep(ms)` ergonomics.
  *
@@ -145,6 +137,17 @@ async function simulateActivity(config: Config, log: ReturnType<typeof makeLogge
  * iteration sees the user's new position and correctly resets the clock.
  */
 export async function runKeeper(config: Config): Promise<void> {
+    // nut.js inserts a configurable delay after every action (default 100ms).
+    // That default would silently more-than-double the duration of every
+    // setPosition and getPosition call. We drive cadence ourselves via
+    // config.stepDelay, so disable nut.js's implicit delay entirely.
+    //
+    // Setting this here (rather than at module load) keeps `keeper.ts` free
+    // of import-time side effects on the shared nut.js singleton — useful
+    // for tests and any future code path that imports this module without
+    // actually running the loop.
+    mouse.config.autoDelayMs = 0;
+
     const log = makeLogger(config.verbose);
     log.info("Teams Status Keeper started. Press Ctrl+C to stop.");