diff --git a/src/courseware/CoursewareContainer.test.jsx b/src/courseware/CoursewareContainer.test.jsx
index 7fbdb56d..f38f5de5 100644
--- a/src/courseware/CoursewareContainer.test.jsx
+++ b/src/courseware/CoursewareContainer.test.jsx
@@ -374,7 +374,7 @@ describe('CoursewareContainer', () => {
       });
 
       it('should navigate between units and check block completion', async () => {
-        axiosMock.onPost(`${courseId}/xblock/${sequenceBlock.id}/handler/xmodule_handler/get_completion`).reply(200, {
+        axiosMock.onPost(`${courseId}/xblock/${sequenceBlock.id}/handler/get_completion`).reply(200, {
           complete: true,
         });
 
diff --git a/src/courseware/data/__factories__/sequenceMetadata.factory.js b/src/courseware/data/__factories__/sequenceMetadata.factory.js
index 8055b74d..ce8173ef 100644
--- a/src/courseware/data/__factories__/sequenceMetadata.factory.js
+++ b/src/courseware/data/__factories__/sequenceMetadata.factory.js
@@ -29,7 +29,6 @@ Factory.define('sequenceMetadata')
   .attr('element_id', ['sequenceBlock'], sequenceBlock => sequenceBlock.block_id)
   .attr('item_id', ['sequenceBlock'], sequenceBlock => sequenceBlock.id)
   .attr('display_name', ['sequenceBlock'], sequenceBlock => sequenceBlock.display_name)
-  .attr('ajax_url', ['sequenceBlock'], sequenceBlock => `${sequenceBlock.student_view_url}/handler/xmodule_handler}`)
   .attr('gated_content', ['sequenceBlock'], sequenceBlock => ({
     gated: false,
     prereq_url: null,
diff --git a/src/courseware/data/api.js b/src/courseware/data/api.js
index 05e798ae..45bad771 100644
--- a/src/courseware/data/api.js
+++ b/src/courseware/data/api.js
@@ -205,48 +205,22 @@ export async function getSequenceMetadata(sequenceId) {
   return normalizeSequenceMetadata(data);
 }
 
-const getSequenceXModuleHandlerUrl = (courseId, sequenceId) => `${getConfig().LMS_BASE_URL}/courses/${courseId}/xblock/${sequenceId}/handler/xmodule_handler`;
+const getSequenceHandlerUrl = (courseId, sequenceId) => `${getConfig().LMS_BASE_URL}/courses/${courseId}/xblock/${sequenceId}/handler`;
 
 export async function getBlockCompletion(courseId, sequenceId, usageKey) {
-  // Post data sent to this endpoint must be url encoded
-  // TODO: Remove the need for this to be the case.
-  // TODO: Ensure this usage of URLSearchParams is working in Internet Explorer
-  const urlEncoded = new URLSearchParams();
-  urlEncoded.append('usage_key', usageKey);
-  const requestConfig = {
-    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
-  };
-
   const { data } = await getAuthenticatedHttpClient().post(
-    `${getSequenceXModuleHandlerUrl(courseId, sequenceId)}/get_completion`,
-    urlEncoded.toString(),
-    requestConfig,
+    `${getSequenceHandlerUrl(courseId, sequenceId)}/get_completion`,
+    { usage_key: usageKey },
   );
-
-  if (data.complete) {
-    return true;
-  }
-
-  return false;
+  return data.complete === true;
 }
 
 export async function postSequencePosition(courseId, sequenceId, activeUnitIndex) {
-  // Post data sent to this endpoint must be url encoded
-  // TODO: Remove the need for this to be the case.
-  // TODO: Ensure this usage of URLSearchParams is working in Internet Explorer
-  const urlEncoded = new URLSearchParams();
-  // Position is 1-indexed on the server and 0-indexed in this app. Adjust here.
-  urlEncoded.append('position', activeUnitIndex + 1);
-  const requestConfig = {
-    headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
-  };
-
   const { data } = await getAuthenticatedHttpClient().post(
-    `${getSequenceXModuleHandlerUrl(courseId, sequenceId)}/goto_position`,
-    urlEncoded.toString(),
-    requestConfig,
+    `${getSequenceHandlerUrl(courseId, sequenceId)}/goto_position`,
+    // Position is 1-indexed on the server and 0-indexed in this app. Adjust here.
+    { position: activeUnitIndex + 1 },
   );
-
   return data;
 }
 
diff --git a/src/courseware/data/redux.test.js b/src/courseware/data/redux.test.js
index 422c8931..dc04f630 100644
--- a/src/courseware/data/redux.test.js
+++ b/src/courseware/data/redux.test.js
@@ -198,7 +198,7 @@ describe('Data layer integration tests', () => {
     });
 
     describe('Test checkBlockCompletion', () => {
-      const getCompletionURL = `${getConfig().LMS_BASE_URL}/courses/${courseId}/xblock/${sequenceId}/handler/xmodule_handler/get_completion`;
+      const getCompletionURL = `${getConfig().LMS_BASE_URL}/courses/${courseId}/xblock/${sequenceId}/handler/get_completion`;
 
       it('Should fail to check completion and log error', async () => {
         axiosMock.onPost(getCompletionURL).networkError();
@@ -227,7 +227,7 @@ describe('Data layer integration tests', () => {
     });
 
     describe('Test saveSequencePosition', () => {
-      const gotoPositionURL = `${getConfig().LMS_BASE_URL}/courses/${courseId}/xblock/${sequenceId}/handler/xmodule_handler/goto_position`;
+      const gotoPositionURL = `${getConfig().LMS_BASE_URL}/courses/${courseId}/xblock/${sequenceId}/handler/goto_position`;
 
       it('Should change and revert sequence model activeUnitIndex in case of error', async () => {
         axiosMock.onPost(gotoPositionURL).networkError();