diff --git a/IDLImporter/IDLImporter.csproj b/IDLImporter/IDLImporter.csproj
index 86ce6f6..5bf20f7 100644
--- a/IDLImporter/IDLImporter.csproj
+++ b/IDLImporter/IDLImporter.csproj
@@ -14,7 +14,7 @@
     <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageReference Include="SIL.ReleaseTasks" Version="2.5.0" PrivateAssets="All" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.1" PrivateAssets="All" />
-    <PackageReference Include="System.CodeDom" Version="6.0.0" />
+    <PackageReference Include="System.CodeDom" Version="9.0.0" />
   </ItemGroup>
 
   <ItemGroup>