diff --git a/src/GeminiLab.Core2.CommandLineParser/GeminiLab.Core2.CommandLineParser.csproj b/src/GeminiLab.Core2.CommandLineParser/GeminiLab.Core2.CommandLineParser.csproj
index 72d2242..4d94659 100644
--- a/src/GeminiLab.Core2.CommandLineParser/GeminiLab.Core2.CommandLineParser.csproj
+++ b/src/GeminiLab.Core2.CommandLineParser/GeminiLab.Core2.CommandLineParser.csproj
@@ -10,7 +10,7 @@
     <AssemblyVersion>2.1.0</AssemblyVersion>
     <Copyright>Copyright © Gemini Laboratory 2017 - 2020</Copyright>
     <FileVersion>2.1.0.0</FileVersion>
-    <Version>2.1.0-dev</Version>
+    <Version>2.1.0-preview.1</Version>
     <LangVersion>8.0</LangVersion>
     <Configurations>Develop;Preview;Release</Configurations>
     <OutputPath>..\..\bin\$(Configuration)\</OutputPath>