diff --git a/QuickLook.Plugin/QuickLook.Plugin.TextViewer/QuickLook.Plugin.TextViewer.csproj b/QuickLook.Plugin/QuickLook.Plugin.TextViewer/QuickLook.Plugin.TextViewer.csproj
index ea390b7..c6f44da 100644
--- a/QuickLook.Plugin/QuickLook.Plugin.TextViewer/QuickLook.Plugin.TextViewer.csproj
+++ b/QuickLook.Plugin/QuickLook.Plugin.TextViewer/QuickLook.Plugin.TextViewer.csproj
@@ -8,7 +8,7 @@
         <FileAlignment>512</FileAlignment>
         <SignAssembly>false</SignAssembly>
         <UseWPF>true</UseWPF>
-        <LangVersion>latest</LangVersion>
+        <LangVersion>preview</LangVersion>
         <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
         <AppendTargetFrameworkToOutputPath>false</AppendTargetFrameworkToOutputPath>
         <GenerateTargetFrameworkAttribute>false</GenerateTargetFrameworkAttribute>