diff --git a/src/Smdn.Net.EchonetLite.Primitives/Smdn.Net.EchonetLite.Primitives.csproj b/src/Smdn.Net.EchonetLite.Primitives/Smdn.Net.EchonetLite.Primitives.csproj
index 327fd25..6ecd5b6 100644
--- a/src/Smdn.Net.EchonetLite.Primitives/Smdn.Net.EchonetLite.Primitives.csproj
+++ b/src/Smdn.Net.EchonetLite.Primitives/Smdn.Net.EchonetLite.Primitives.csproj
@@ -9,7 +9,7 @@ SPDX-License-Identifier: MIT
     <TargetFrameworks>netstandard2.1;net8.0</TargetFrameworks>
     <VersionPrefix>2.0.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
-    <!-- <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion> -->
+    <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion>
     <Nullable>enable</Nullable>
     <RootNamespace/> <!-- empty the root namespace so that the namespace is determined only by the directory name, for code style rule IDE0030 -->
     <NoWarn>CS1591;$(NoWarn)</NoWarn> <!-- CS1591: Missing XML comment for publicly visible type or member 'Type_or_Member' -->
diff --git a/src/Smdn.Net.EchonetLite.RouteB.Primitives/Smdn.Net.EchonetLite.RouteB.Primitives.csproj b/src/Smdn.Net.EchonetLite.RouteB.Primitives/Smdn.Net.EchonetLite.RouteB.Primitives.csproj
index 0875e87..71f6b75 100644
--- a/src/Smdn.Net.EchonetLite.RouteB.Primitives/Smdn.Net.EchonetLite.RouteB.Primitives.csproj
+++ b/src/Smdn.Net.EchonetLite.RouteB.Primitives/Smdn.Net.EchonetLite.RouteB.Primitives.csproj
@@ -8,7 +8,7 @@ SPDX-License-Identifier: MIT
     <TargetFrameworks>netstandard2.1;net8.0</TargetFrameworks>
     <VersionPrefix>2.0.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
-    <!-- <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion> -->
+    <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion>
     <Nullable>enable</Nullable>
     <RootNamespace/> <!-- empty the root namespace so that the namespace is determined only by the directory name, for code style rule IDE0030 -->
     <NoWarn>CS1591;$(NoWarn)</NoWarn> <!-- CS1591: Missing XML comment for publicly visible type or member 'Type_or_Member' -->
diff --git a/src/Smdn.Net.EchonetLite.RouteB/Smdn.Net.EchonetLite.RouteB.csproj b/src/Smdn.Net.EchonetLite.RouteB/Smdn.Net.EchonetLite.RouteB.csproj
index dc91b46..3d2ded6 100644
--- a/src/Smdn.Net.EchonetLite.RouteB/Smdn.Net.EchonetLite.RouteB.csproj
+++ b/src/Smdn.Net.EchonetLite.RouteB/Smdn.Net.EchonetLite.RouteB.csproj
@@ -8,7 +8,7 @@ SPDX-License-Identifier: MIT
     <TargetFrameworks>netstandard2.1;net8.0</TargetFrameworks>
     <VersionPrefix>2.0.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
-    <!-- <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion> -->
+    <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion>
     <Nullable>enable</Nullable>
     <RootNamespace/> <!-- empty the root namespace so that the namespace is determined only by the directory name, for code style rule IDE0030 -->
     <NoWarn>CS1591;$(NoWarn)</NoWarn> <!-- CS1591: Missing XML comment for publicly visible type or member 'Type_or_Member' -->
diff --git a/src/Smdn.Net.EchonetLite/Smdn.Net.EchonetLite.csproj b/src/Smdn.Net.EchonetLite/Smdn.Net.EchonetLite.csproj
index 6d9d0d3..9421b49 100644
--- a/src/Smdn.Net.EchonetLite/Smdn.Net.EchonetLite.csproj
+++ b/src/Smdn.Net.EchonetLite/Smdn.Net.EchonetLite.csproj
@@ -10,7 +10,7 @@ SPDX-License-Identifier: MIT
     <TargetFrameworks>netstandard2.1;net8.0</TargetFrameworks>
     <VersionPrefix>2.0.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
-    <!-- <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion> -->
+    <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion>
     <Nullable>enable</Nullable>
     <RootNamespace/> <!-- empty the root namespace so that the namespace is determined only by the directory name, for code style rule IDE0030 -->
     <NoWarn>CS1591;$(NoWarn)</NoWarn> <!-- CS1591: Missing XML comment for publicly visible type or member 'Type_or_Member' -->
diff --git a/src/Smdn.Net.SmartMeter/Smdn.Net.SmartMeter.csproj b/src/Smdn.Net.SmartMeter/Smdn.Net.SmartMeter.csproj
index 393a326..3c9fcc7 100644
--- a/src/Smdn.Net.SmartMeter/Smdn.Net.SmartMeter.csproj
+++ b/src/Smdn.Net.SmartMeter/Smdn.Net.SmartMeter.csproj
@@ -8,7 +8,7 @@ SPDX-License-Identifier: MIT
     <TargetFrameworks>netstandard2.1;net8.0</TargetFrameworks>
     <VersionPrefix>2.0.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
-    <!-- <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion> -->
+    <PackageValidationBaselineVersion>2.0.0</PackageValidationBaselineVersion>
     <Nullable>enable</Nullable>
     <RootNamespace/> <!-- empty the root namespace so that the namespace is determined only by the directory name, for code style rule IDE0030 -->
     <NoWarn>CS1591;$(NoWarn)</NoWarn> <!-- CS1591: Missing XML comment for publicly visible type or member 'Type_or_Member' -->