diff --git a/Dockerfile b/Dockerfile
index 668f7b6f6..c3798aac6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,7 @@
 #
 # See CONTRIBUTING.md
 #
-FROM mcr.microsoft.com/dotnet/sdk:7.0
+FROM mcr.microsoft.com/dotnet/sdk:9.0
 
 ENV DEBIAN_FRONTEND=noninteractive
 
diff --git a/dotnet/Gherkin/Gherkin.csproj b/dotnet/Gherkin/Gherkin.csproj
index a8be9f321..d16cb036d 100644
--- a/dotnet/Gherkin/Gherkin.csproj
+++ b/dotnet/Gherkin/Gherkin.csproj
@@ -33,7 +33,7 @@
   </PropertyGroup>
 
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.0'">
-    <PackageReference Include="System.Text.Json" Version="6.0.0" />
+    <PackageReference Include="System.Text.Json" Version="8.0.4" />
   </ItemGroup>
 
   <ItemGroup>