diff --git a/Tasks/UrlTester/UrlTester.csproj b/Tasks/UrlTester/UrlTester.csproj
index cd7fcc1..9e7e345 100644
--- a/Tasks/UrlTester/UrlTester.csproj
+++ b/Tasks/UrlTester/UrlTester.csproj
@@ -6,6 +6,10 @@
       <ImplicitUsings>enable</ImplicitUsings>
       <Nullable>disable</Nullable>
     </PropertyGroup>
+
+    <ItemGroup>
+      <PackageReference Include="System.ObjectModel" Version="4.3.0" />
+    </ItemGroup>
   
   </Project>
   
\ No newline at end of file