diff --git a/src/TestableHttpClient/TestableHttpClient.csproj b/src/TestableHttpClient/TestableHttpClient.csproj
index 1c462a4..4ccda12 100644
--- a/src/TestableHttpClient/TestableHttpClient.csproj
+++ b/src/TestableHttpClient/TestableHttpClient.csproj
@@ -33,8 +33,8 @@
 
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
     <PackageReference Include="System.Net.Http" Version="4.3.4" />
-    <PackageReference Include="System.Text.Json" Version="4.7.2" />
-    <PackageReference Include="System.Text.Encodings.Web" Version="4.7.2" />
+    <PackageReference Include="System.Text.Json" Version="9.0.0" />
+    <PackageReference Include="System.Text.Encodings.Web" Version="9.0.0" />
     <PackageReference Include="Perfors.UnreachableException" Version="1.0.0" />
     <PackageReference Include="PolyKit.Embedded" Version="3.0.9" />
   </ItemGroup>
diff --git a/test/TestableHttpClient.Tests/TestableHttpClient.Tests.csproj b/test/TestableHttpClient.Tests/TestableHttpClient.Tests.csproj
index a808876..5a0df93 100644
--- a/test/TestableHttpClient.Tests/TestableHttpClient.Tests.csproj
+++ b/test/TestableHttpClient.Tests/TestableHttpClient.Tests.csproj
@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">
-    <PackageReference Include="System.Net.Http.Json" Version="8.0.1" />
+    <PackageReference Include="System.Net.Http.Json" Version="9.0.0" />
   </ItemGroup>
 
   <ItemGroup>