diff --git a/app/assets/javascripts/merge_requests/utils/reviewer_positions.js b/app/assets/javascripts/merge_requests/utils/reviewer_positions.js
index ce07c3c6e81b918496ae53417242d0340b10d462..ec9bfa66ee9d8a923017f642b5f5464bb67e0c1b 100644
--- a/app/assets/javascripts/merge_requests/utils/reviewer_positions.js
+++ b/app/assets/javascripts/merge_requests/utils/reviewer_positions.js
@@ -11,8 +11,15 @@ export function setReviewersForList({ issuableId, listId, reviewers = [] } = {})
 export function getReviewersForList({ issuableId, listId } = {}) {
   const id = cacheId({ issuableId, listId });
   const list = window.sessionStorage.getItem(id);
+  let parsedList;
 
-  return list ? JSON.parse(list) : [];
+  try {
+    parsedList = list ? JSON.parse(list) : [];
+  } catch {
+    parsedList = [];
+  }
+
+  return parsedList;
 }
 
 export function suggestedPosition({ username, list = [] } = {}) {
diff --git a/spec/frontend/merge_requests/utils/reviewer_positions_spec.js b/spec/frontend/merge_requests/utils/reviewer_positions_spec.js
index 0ab3c14c85f08f8e11b789977038e0f6f3fae3f7..ecb1c59fd86e810fa9ce0dc6190bbe09fb30642c 100644
--- a/spec/frontend/merge_requests/utils/reviewer_positions_spec.js
+++ b/spec/frontend/merge_requests/utils/reviewer_positions_spec.js
@@ -17,6 +17,7 @@ describe('reviewer_positions utility', () => {
       getItem: jest.fn().mockImplementation((key) => {
         const vals = {
           'MergeRequest/123/test-list-id': mockReviewersString,
+          'MergeRequest/123/invalid-data': '#',
         };
 
         return vals[key];
@@ -64,6 +65,15 @@ describe('reviewer_positions utility', () => {
 
       expect(result).toEqual([]);
     });
+
+    it('returns an empty array when the data in storage is not a valid JSON string', () => {
+      const result = getReviewersForList({
+        issuableId: mockIssuableId,
+        listId: 'invalid-data',
+      });
+
+      expect(result).toEqual([]);
+    });
   });
 
   describe('suggestedPosition', () => {