diff --git a/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.csproj b/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.csproj
index d35d83bb..db058033 100644
--- a/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.csproj
+++ b/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.csproj
@@ -19,7 +19,7 @@
 	</ItemGroup>
 
 	<ItemGroup>
-		<PackageReference Include="MessagePack" Version="1.9.11" />
+		<PackageReference Include="MessagePack" Version="2.5.187" />
 		<PackageReference Include="MessagePackAnalyzer" Version="1.6.0" />
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
 		<PackageReference Include="Moq" Version="4.9.0" />
diff --git a/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net6.csproj b/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net6.csproj
index b7312df4..77d396bd 100644
--- a/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net6.csproj
+++ b/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net6.csproj
@@ -19,7 +19,7 @@
   </ItemGroup>
 
   <ItemGroup>
-	  <PackageReference Include="MessagePack" Version="1.7.3.4" />
+	  <PackageReference Include="MessagePack" Version="2.5.187" />
 	  <PackageReference Include="MessagePackAnalyzer" Version="1.6.0" />
 	  <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="6.0.0" />
 	  <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
diff --git a/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net7.csproj b/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net7.csproj
index 1f4c94fa..b08fe6c2 100644
--- a/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net7.csproj
+++ b/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net7.csproj
@@ -19,7 +19,7 @@
   </ItemGroup>
 
   <ItemGroup>
-	  <PackageReference Include="MessagePack" Version="1.7.3.4" />
+	  <PackageReference Include="MessagePack" Version="2.5.187" />
 	  <PackageReference Include="MessagePackAnalyzer" Version="1.6.0" />
 	  <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="7.0.0" />
 	  <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
diff --git a/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net8.csproj b/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net8.csproj
index 7ce28872..01f40f31 100644
--- a/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net8.csproj
+++ b/src/Senparc.CO2NET.Cache.Redis.Tests/Senparc.CO2NET.Cache.Redis.Tests.net8.csproj
@@ -19,7 +19,7 @@
   </ItemGroup>
 
   <ItemGroup>
-	  <PackageReference Include="MessagePack" Version="2.5.171" />
+	  <PackageReference Include="MessagePack" Version="2.5.187" />
 	  <PackageReference Include="MessagePackAnalyzer" Version="2.5.171">
 	    <PrivateAssets>all</PrivateAssets>
 	    <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>