diff --git a/scripts/check-miner-package.mjs b/scripts/check-miner-package.mjs
index cc284ba515..1bb6ec7beb 100644
--- a/scripts/check-miner-package.mjs
+++ b/scripts/check-miner-package.mjs
@@ -6,7 +6,9 @@ import { fileURLToPath } from "node:url";
 
 const ALLOWED = [
   /^bin\/gittensory-miner\.js$/,
-  /^lib\/[a-z0-9-]+\.(js|d\.ts)$/,
+  // One optional level of subdirectory (e.g. lib/calibration/index.js, #2332) alongside the original flat
+  // lib/<name>.js layout -- both forms ship real runtime/type files, never build tooling or config.
+  /^lib\/([a-z0-9-]+\/)?[a-z0-9-]+\.(js|d\.ts)$/,
   /^package\.json$/,
   /^README\.md$/,
 ];
@@ -26,7 +28,7 @@ export function validateMinerPackFileList(files, readContent) {
   for (const required of REQUIRED) {
     if (!paths.includes(required)) throw new Error(`Miner package is missing required file: ${required}`);
   }
-  if (!paths.some((file) => /^lib\/[a-z0-9-]+\.js$/.test(file))) {
+  if (!paths.some((file) => /^lib\/([a-z0-9-]+\/)?[a-z0-9-]+\.js$/.test(file))) {
     throw new Error("Miner package is missing lib/*.js artifacts");
   }
   return paths;
diff --git a/test/unit/check-miner-package.test.ts b/test/unit/check-miner-package.test.ts
index 1354932cc9..7c2f7f1c99 100644
--- a/test/unit/check-miner-package.test.ts
+++ b/test/unit/check-miner-package.test.ts
@@ -35,6 +35,33 @@ describe("check-miner-package script", () => {
     expect(result.out).toContain("Unexpected file in miner package: scripts/extra.mjs");
   });
 
+  it("REGRESSION (main was red after #3704): accepts a lib module split into a one-level subdirectory", () => {
+    const result = runChecker({
+      CHECK_MINER_PACK_TEST_FILES: JSON.stringify([
+        "package.json",
+        "bin/gittensory-miner.js",
+        "lib/calibration/index.js",
+        "lib/calibration/index.d.ts",
+      ]),
+      CHECK_MINER_PACK_TEST_CONTENT: "{}",
+    });
+    expect(result.status).toBe(0);
+    expect(result.out).toContain("lib/calibration/index.js");
+  });
+
+  it("still rejects a file nested two levels deep under lib/", () => {
+    const result = runChecker({
+      CHECK_MINER_PACK_TEST_FILES: JSON.stringify([
+        "package.json",
+        "bin/gittensory-miner.js",
+        "lib/cli.js",
+        "lib/calibration/nested/index.js",
+      ]),
+    });
+    expect(result.status).toBe(1);
+    expect(result.out).toContain("Unexpected file in miner package: lib/calibration/nested/index.js");
+  });
+
   it("rejects a package missing the CLI bin", () => {
     const result = runChecker({
       CHECK_MINER_PACK_TEST_FILES: JSON.stringify(["package.json", "lib/cli.js"]),