diff --git a/BO4E/BO4E.csproj b/BO4E/BO4E.csproj
index 09d12b6a..146d730f 100644
--- a/BO4E/BO4E.csproj
+++ b/BO4E/BO4E.csproj
@@ -87,7 +87,7 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Portable.System.DateTimeOnly" Version="8.0.2" />
+    <PackageReference Include="Portable.System.DateTimeOnly" Version="9.0.0" />
     <PackageReference Include="protobuf-net" Version="3.2.45" />
     <PackageReference Include="SourceLink.Copy.PdbFiles" Version="2.8.3" PrivateAssets="All" />
     <PackageReference Include="System.ComponentModel.Annotations" Version="5.0.0" />