diff --git a/src/api/apiService.ts b/src/api/apiService.ts
index 6a5bdbd..595927b 100644
--- a/src/api/apiService.ts
+++ b/src/api/apiService.ts
@@ -39,7 +39,7 @@ export const getTaskList = async (): Promise<TaskListResponse> => {
 export const completeTask = async (taskId: string, childId: string): Promise<void> => {
   const params = new URLSearchParams();
   params.append('childId', childId);
-  const response = await api.post(`/task/${taskId}/complete`, params);
+  const response = await api.post(`/task/${taskId}/complete`, {}, { params });
   if (response.status !== 200) {
     throw new Error('タスクの完了に失敗しました');
   }