diff --git a/src/api/__tests__/lists.spec.ts b/src/api/__tests__/lists.spec.ts
index c1e5c73..7dc4f50 100644
--- a/src/api/__tests__/lists.spec.ts
+++ b/src/api/__tests__/lists.spec.ts
@@ -157,7 +157,7 @@ describe('lists API', () => {
     } as unknown as Response)
     global.fetch = fetchMock
 
-    await addUserToListApi({ list_id: 'list-1', user_id: 'user-1' })
+    await addUserToListApi({ list_id: 'list-1', email: 'user@example.com' })
 
     expect(fetchMock).toHaveBeenCalledWith(
       `${API_BASE_URL}/lists/user`,
@@ -172,7 +172,7 @@ describe('lists API', () => {
     } as unknown as Response)
     global.fetch = fetchMock
 
-    await removeUserFromListApi({ list_id: 'list-1', user_id: 'user-1' })
+    await removeUserFromListApi({ list_id: 'list-1', email: 'user@example.com' })
 
     expect(fetchMock).toHaveBeenCalledWith(
       `${API_BASE_URL}/lists/user`,
diff --git a/src/stores/lists.ts b/src/stores/lists.ts
index 255d6ad..9055252 100644
--- a/src/stores/lists.ts
+++ b/src/stores/lists.ts
@@ -142,20 +142,20 @@ export const useListsStore = defineStore('lists', () => {
     void sync()
   }
 
-  async function addUserToList(listId: string, userId: string) {
+  async function addUserToList(listId: string, email: string) {
     await enqueue({
       type: 'addUserToList',
-      payload: { list_id: listId, user_id: userId },
+      payload: { list_id: listId, email },
       localListId: listId,
     })
     await refresh()
     void sync()
   }
 
-  async function removeUserFromList(listId: string, userId: string) {
+  async function removeUserFromList(listId: string, email: string) {
     await enqueue({
       type: 'removeUserFromList',
-      payload: { list_id: listId, user_id: userId },
+      payload: { list_id: listId, email },
       localListId: listId,
     })
     await refresh()
@@ -255,11 +255,11 @@ export const useListsStore = defineStore('lists', () => {
         break
       }
       case 'addUserToList': {
-        await addUserToListApi(entry.payload as { list_id: string; user_id: string })
+        await addUserToListApi(entry.payload as { list_id: string; email: string })
         break
       }
       case 'removeUserFromList': {
-        await removeUserFromListApi(entry.payload as { list_id: string; user_id: string })
+        await removeUserFromListApi(entry.payload as { list_id: string; email: string })
         break
       }
     }
diff --git a/src/types/list.ts b/src/types/list.ts
index 79a156d..0bf7c75 100644
--- a/src/types/list.ts
+++ b/src/types/list.ts
@@ -36,10 +36,10 @@ export interface SetListItemCompletedPayload {
 
 export interface AddUserToListPayload {
   list_id: string
-  user_id: string
+  email: string
 }
 
 export interface RemoveUserFromListPayload {
   list_id: string
-  user_id: string
+  email: string
 }