diff --git a/source/Directory.Build.props b/source/Directory.Build.props
index 1c68137..e3c85f2 100644
--- a/source/Directory.Build.props
+++ b/source/Directory.Build.props
@@ -22,7 +22,7 @@
 	</PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Polyfill" Version="10.3.0" PrivateAssets="all" />
+    <PackageReference Include="Polyfill" Version="10.5.1" PrivateAssets="all" />
   </ItemGroup>
 
   <Import Project="$(MSBuildThisFileDirectory)DefaultCSharp\projects\DefaultCSharp.props" />