diff --git a/backend/app/Http/Controllers/Api/ChildrenController.php b/backend/app/Http/Controllers/Api/ChildrenController.php
index 0848da70..e96cf1f0 100644
--- a/backend/app/Http/Controllers/Api/ChildrenController.php
+++ b/backend/app/Http/Controllers/Api/ChildrenController.php
@@ -613,15 +613,23 @@ class ChildrenController extends Controller {
             return ['status_code' => 422, 'error_messages' => $validate->errors()];
         }
 
-        $update = [
-            'password' => Hash::make($r->password),
-        ];
-
         try {
-            Child::where('id', (int)$child_id)->update($update);
+            DB::beginTransaction();
+
+            $child = Child::find((int)$child_id);
+            $child->password = Hash::make($r->password);
+            $child->save();
+
+            if (isset($r->token)) {
+                $telact = TelActivation::where('token', $r->token);
+                $telact->delete();
+            }
+
+            DB::commit();
         } catch (\Throwable $e) {
             // 失敗
             Log::critical($e->getMessage());
+            DB::rollback();
             return ['status_code' => 400, 'error_messages' => ['パスワードの更新に失敗しました。']];
         }