diff --git a/dictation_server/db/migrations/054-add_license_index.sql b/dictation_server/db/migrations/054-add_license_index.sql
new file mode 100644
index 0000000..f08b2e9
--- /dev/null
+++ b/dictation_server/db/migrations/054-add_license_index.sql
@@ -0,0 +1,13 @@
+-- +migrate Up
+ALTER TABLE `license_orders` ADD INDEX `idx_po_number` (po_number);
+ALTER TABLE `license_orders` ADD INDEX `idx_from_account_id` (from_account_id);
+ALTER TABLE `license_orders` ADD INDEX `idx_status` (status);
+ALTER TABLE `card_licenses` ADD INDEX `idx_card_license_key` (card_license_key);
+ALTER TABLE `licenses` ADD INDEX `idx_status` (status);
+
+-- +migrate Down
+ALTER TABLE `license_orders` DROP INDEX `idx_po_number`;
+ALTER TABLE `license_orders` DROP INDEX `idx_from_account_id`;
+ALTER TABLE `license_orders` DROP INDEX `idx_status`;
+ALTER TABLE `card_licenses` DROP INDEX `idx_card_license_key`;
+ALTER TABLE `licenses` DROP INDEX `idx_status`;
\ No newline at end of file
diff --git a/dictation_server/src/repositories/licenses/licenses.repository.service.ts b/dictation_server/src/repositories/licenses/licenses.repository.service.ts
index a5e03a3..2a0c328 100644
--- a/dictation_server/src/repositories/licenses/licenses.repository.service.ts
+++ b/dictation_server/src/repositories/licenses/licenses.repository.service.ts
@@ -81,6 +81,7 @@ export class LicensesRepositoryService {
               },
             ],
             comment: `${context.getTrackingId()}_${new Date().toUTCString()}`,
+            lock: { mode: 'pessimistic_write' },
           });
         // 重複があった場合はエラーを返却する
         if (isPoNumberDuplicated) {
@@ -193,6 +194,7 @@ export class LicensesRepositoryService {
             card_license_key: In(generateKeys),
           },
           comment: `${context.getTrackingId()}_${new Date().toUTCString()}`,
+          lock: { mode: 'pessimistic_write' },
         });
         if (existingCardLicenses.length > 0) {
           // 重複分を配列から削除
@@ -292,6 +294,7 @@ export class LicensesRepositoryService {
           card_license_key: licenseKey,
         },
         comment: `${context.getTrackingId()}_${new Date().toUTCString()}`,
+        lock: { mode: 'pessimistic_write' },
       });
       // カードライセンスが存在しなければエラー
       if (!targetCardLicense) {
@@ -602,6 +605,7 @@ export class LicensesRepositoryService {
           allocated_user_id: userId,
         },
         comment: `${context.getTrackingId()}_${new Date().toUTCString()}`,
+        lock: { mode: 'pessimistic_write' },
       });
 
       // 既にライセンスが割り当てられているなら、割り当てを解除
@@ -717,6 +721,7 @@ export class LicensesRepositoryService {
           status: LICENSE_ALLOCATED_STATUS.ALLOCATED,
         },
         comment: `${context.getTrackingId()}_${new Date().toUTCString()}`,
+        lock: { mode: 'pessimistic_write' },
       });
 
       // ライセンスが割り当てられていない場合はエラー
@@ -776,6 +781,7 @@ export class LicensesRepositoryService {
           status: LICENSE_ISSUE_STATUS.ISSUE_REQUESTING,
         },
         comment: `${context.getTrackingId()}_${new Date().toUTCString()}`,
+        lock: { mode: 'pessimistic_write' },
       });
 
       // キャンセル対象の注文が存在しない場合エラー