diff --git a/skills/hyperframes-animation/scripts/animation-map.mjs b/skills/hyperframes-animation/scripts/animation-map.mjs
index f95bb09331..a9a3612df7 100644
--- a/skills/hyperframes-animation/scripts/animation-map.mjs
+++ b/skills/hyperframes-animation/scripts/animation-map.mjs
@@ -51,7 +51,7 @@ const server = await createFileServer({ projectDir: COMP_DIR, port: 0 });
 const session = await createCaptureSession(
   server.url,
   OUT_DIR,
-  { width: WIDTH, height: HEIGHT, fps: FPS, format: "png" },
+  { width: WIDTH, height: HEIGHT, fps: { num: FPS, den: 1 }, format: "png" },
   null,
 );
 await initializeSession(session);
diff --git a/skills/hyperframes-animation/scripts/animation-map.test.mjs b/skills/hyperframes-animation/scripts/animation-map.test.mjs
new file mode 100644
index 0000000000..5ffd62e1e3
--- /dev/null
+++ b/skills/hyperframes-animation/scripts/animation-map.test.mjs
@@ -0,0 +1,66 @@
+import assert from "node:assert/strict";
+import { spawnSync } from "node:child_process";
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { dirname, join, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+import { describe, it } from "node:test";
+
+const REPO_ROOT = resolve(dirname(fileURLToPath(import.meta.url)), "../../..");
+const HELPERS = [
+  join(REPO_ROOT, "skills", "hyperframes-animation", "scripts", "animation-map.mjs"),
+  join(REPO_ROOT, "skills", "hyperframes-creative", "scripts", "contrast-report.mjs"),
+];
+
+describe("HyperFrames skill helpers", () => {
+  for (const helper of HELPERS)
+    it(`${helper.split("/").at(-1)} passes a rational frame rate`, () => {
+      const root = mkdtempSync(join(tmpdir(), "hyperframes-skill-helper-test-"));
+      const packageDir = join(root, "node_modules", "@hyperframes", "producer");
+      const sharpPackageDir = join(root, "node_modules", "sharp");
+      const compositionDir = join(root, "composition");
+      mkdirSync(packageDir, { recursive: true });
+      mkdirSync(sharpPackageDir, { recursive: true });
+      mkdirSync(compositionDir, { recursive: true });
+      writeFileSync(
+        join(packageDir, "package.json"),
+        JSON.stringify({ name: "@hyperframes/producer", type: "module", exports: "./index.mjs" }),
+      );
+      writeFileSync(
+        join(packageDir, "index.mjs"),
+        [
+          'export async function createFileServer() { return { url: "http://test", close() {} }; }',
+          "export async function createCaptureSession(_url, _out, options) {",
+          "  throw new Error(`CAPTURE_OPTIONS=${JSON.stringify(options)}`);",
+          "}",
+          "export async function initializeSession() {}",
+          "export async function closeCaptureSession() {}",
+          "export async function getCompositionDuration() { return 0; }",
+        ].join("\n"),
+      );
+      writeFileSync(
+        join(sharpPackageDir, "package.json"),
+        JSON.stringify({ name: "sharp", type: "module", exports: "./index.mjs" }),
+      );
+      writeFileSync(join(sharpPackageDir, "index.mjs"), "export default function sharp() {}\n");
+
+      try {
+        const result = spawnSync(
+          process.execPath,
+          [helper, compositionDir, "--fps", "24", "--out", join(root, "output")],
+          {
+            encoding: "utf8",
+            env: {
+              ...process.env,
+              HYPERFRAMES_SKILL_NODE_MODULES: join(root, "node_modules"),
+            },
+          },
+        );
+        const output = `${result.stdout}\n${result.stderr}`;
+        assert.notEqual(result.status, 0);
+        assert.match(output, /CAPTURE_OPTIONS=.*"fps":\{"num":24,"den":1\}/);
+      } finally {
+        rmSync(root, { recursive: true, force: true });
+      }
+    });
+});
diff --git a/skills/hyperframes-creative/scripts/contrast-report.mjs b/skills/hyperframes-creative/scripts/contrast-report.mjs
index 1f7db29355..17804325fc 100644
--- a/skills/hyperframes-creative/scripts/contrast-report.mjs
+++ b/skills/hyperframes-creative/scripts/contrast-report.mjs
@@ -82,7 +82,7 @@ const server = await createFileServer({ projectDir: COMP_DIR, port: 0 });
 const session = await createCaptureSession(
   server.url,
   OUT_DIR,
-  { width: WIDTH, height: HEIGHT, fps: FPS, format: "png" },
+  { width: WIDTH, height: HEIGHT, fps: { num: FPS, den: 1 }, format: "png" },
   null,
 );
 await initializeSession(session);