diff --git a/tests/TemporalioSamples.Tests.csproj b/tests/TemporalioSamples.Tests.csproj
index 01668d6..d56270a 100644
--- a/tests/TemporalioSamples.Tests.csproj
+++ b/tests/TemporalioSamples.Tests.csproj
@@ -19,6 +19,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <PackageReference Include="System.Text.Json" Version="6.0.10" />
     <ProjectReference Include="..\src\ActivitySimple\TemporalioSamples.ActivitySimple.csproj" />
     <ProjectReference Include="..\src\ActivityWorker\TemporalioSamples.ActivityWorker.csproj" />
     <ProjectReference Include="..\src\Bedrock\Entity\TemporalioSamples.Bedrock.Entity.csproj" />