diff --git a/extension/background/canvas-crawler.cjs b/extension/background/canvas-crawler.cjs
index 23529c1..2f39c99 100644
--- a/extension/background/canvas-crawler.cjs
+++ b/extension/background/canvas-crawler.cjs
@@ -13,14 +13,14 @@ function stripHtml(html) {
     .trim();
 }
 
-async function crawlCanvasCourse(origin, courseId, fetchImpl = fetch) {
+async function crawlCanvasCourse(origin, courseId) {
   if (!origin || !courseId) {
     throw new Error('Canvas origin and courseId are required for course crawling.');
   }
 
   // 1. Fetch Course details & syllabus
   const courseUrl = `${origin}/api/v1/courses/${courseId}?include[]=syllabus_body`;
-  const courseRes = await fetchImpl(courseUrl, { credentials: 'include' });
+  const courseRes = await fetch(courseUrl, { credentials: 'include' });
   if (!courseRes.ok) {
     throw new Error(`Failed to fetch Canvas course info (${courseRes.status})`);
   }
@@ -30,7 +30,7 @@ async function crawlCanvasCourse(origin, courseId, fetchImpl = fetch) {
   const assignmentsUrl = `${origin}/api/v1/courses/${courseId}/assignments?per_page=50`;
   let assignments = [];
   try {
-    const assignRes = await fetchImpl(assignmentsUrl, { credentials: 'include' });
+    const assignRes = await fetch(assignmentsUrl, { credentials: 'include' });
     if (assignRes.ok) {
       const assignJson = await assignRes.json();
       if (Array.isArray(assignJson)) {
diff --git a/extension/background/canvas-crawler.js b/extension/background/canvas-crawler.js
index 0c48f1a..8f0a21e 100644
--- a/extension/background/canvas-crawler.js
+++ b/extension/background/canvas-crawler.js
@@ -13,14 +13,14 @@ export function stripHtml(html) {
     .trim();
 }
 
-export async function crawlCanvasCourse(origin, courseId, fetchImpl = fetch) {
+export async function crawlCanvasCourse(origin, courseId) {
   if (!origin || !courseId) {
     throw new Error('Canvas origin and courseId are required for course crawling.');
   }
 
   // 1. Fetch Course details & syllabus
   const courseUrl = `${origin}/api/v1/courses/${courseId}?include[]=syllabus_body`;
-  const courseRes = await fetchImpl(courseUrl, { credentials: 'include' });
+  const courseRes = await fetch(courseUrl, { credentials: 'include' });
   if (!courseRes.ok) {
     throw new Error(`Failed to fetch Canvas course info (${courseRes.status})`);
   }
@@ -30,7 +30,7 @@ export async function crawlCanvasCourse(origin, courseId, fetchImpl = fetch) {
   const assignmentsUrl = `${origin}/api/v1/courses/${courseId}/assignments?per_page=50`;
   let assignments = [];
   try {
-    const assignRes = await fetchImpl(assignmentsUrl, { credentials: 'include' });
+    const assignRes = await fetch(assignmentsUrl, { credentials: 'include' });
     if (assignRes.ok) {
       const assignJson = await assignRes.json();
       if (Array.isArray(assignJson)) {
diff --git a/test/test-crawler.js b/test/test-crawler.js
index 5665e0d..c5445d6 100644
--- a/test/test-crawler.js
+++ b/test/test-crawler.js
@@ -32,7 +32,10 @@ const mockFetch = async (url, options) => {
 };
 
 (async () => {
-  const courseData = await crawlCanvasCourse('https://canvas.instructure.com', '12345', mockFetch);
+  const originalFetch = global.fetch;
+  global.fetch = mockFetch;
+
+  const courseData = await crawlCanvasCourse('https://canvas.instructure.com', '12345');
   assert.strictEqual(courseData.title, 'Biology 101: Cell Systems');
   assert.ok(fetchOptionsPassed.every(opt => opt && opt.credentials === 'include'), 'fetchImpl must include credentials');
   assert.ok(courseData.syllabus.includes('Analyze cellular metabolism'));
@@ -43,7 +46,7 @@ const mockFetch = async (url, options) => {
   // Test 2.5: Missing Error Path Test for crawlCanvasCourse
   let caughtError1 = false;
   try {
-    await crawlCanvasCourse(null, '12345', mockFetch);
+    await crawlCanvasCourse(null, '12345');
   } catch (err) {
     caughtError1 = true;
     assert.strictEqual(err.message, 'Canvas origin and courseId are required for course crawling.');
@@ -52,7 +55,7 @@ const mockFetch = async (url, options) => {
 
   let caughtError2 = false;
   try {
-    await crawlCanvasCourse('https://canvas.instructure.com', null, mockFetch);
+    await crawlCanvasCourse('https://canvas.instructure.com', null);
   } catch (err) {
     caughtError2 = true;
     assert.strictEqual(err.message, 'Canvas origin and courseId are required for course crawling.');
@@ -75,12 +78,14 @@ const mockFetch = async (url, options) => {
 
   let errorThrown = false;
   try {
-    await crawlCanvasCourse('https://canvas.instructure.com', 'invalid-id', mockFailedFetch);
+    global.fetch = mockFailedFetch;
+    await crawlCanvasCourse('https://canvas.instructure.com', 'invalid-id');
   } catch (err) {
     errorThrown = true;
     assert.strictEqual(err.message, 'Failed to fetch Canvas course info (404)');
   }
   assert.ok(errorThrown, 'Expected an error to be thrown for failed fetch');
+  global.fetch = originalFetch;
 
   console.log('✅ Task 2 Canvas crawler tests passed.');
 })();