diff --git a/.github/workflows/test-contract.yml b/.github/workflows/test-contract.yml
index 47c9cac..5484265 100644
--- a/.github/workflows/test-contract.yml
+++ b/.github/workflows/test-contract.yml
@@ -29,6 +29,8 @@ jobs:
       - name: Run Hardhat tests
         run: npx hardhat test
         working-directory: ./pkgs/contract
+        env:
+          PRIVATE_KEY: "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"
 
       # ガスレポートをアーティファクトとして保存
       - name: Upload Gas Report
diff --git a/pkgs/contract/.env.example b/pkgs/contract/.env.example
index 17ab3ec..afd7b8c 100644
--- a/pkgs/contract/.env.example
+++ b/pkgs/contract/.env.example
@@ -1,4 +1,4 @@
-PRIVATE_KEY="xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80"
+PRIVATE_KEY=""
 ETHERSCAN_API_KEY=""
 ALCHEMY_API_KEY=""
 GAS_REPORT=