diff --git a/Agent.Tests/Agent.Tests.csproj b/Agent.Tests/Agent.Tests.csproj
index 9d0e0d5..86f4979 100644
--- a/Agent.Tests/Agent.Tests.csproj
+++ b/Agent.Tests/Agent.Tests.csproj
@@ -10,7 +10,7 @@
 	<ItemGroup>
 		<PackageReference Include="Microsoft.Extensions.Configuration" Version="8.0.0"/>
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1"/>
-		<PackageReference Include="NSubstitute" Version="5.1.0"/>
+		<PackageReference Include="NSubstitute" Version="5.3.0"/>
 		<PackageReference Include="xunit" Version="2.9.2"/>
 		<PackageReference Include="xunit.runner.visualstudio" Version="2.8.2"/>
 		<PackageReference Include="coverlet.collector" Version="6.0.2"/>
diff --git a/Middleware.Tests/Middleware.Tests.csproj b/Middleware.Tests/Middleware.Tests.csproj
index 0ec3ccb..de0f3eb 100644
--- a/Middleware.Tests/Middleware.Tests.csproj
+++ b/Middleware.Tests/Middleware.Tests.csproj
@@ -11,7 +11,7 @@
 		<PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="8.0.1" />
 		<PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.2" />
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
-		<PackageReference Include="NSubstitute" Version="5.1.0" />
+		<PackageReference Include="NSubstitute" Version="5.3.0" />
 		<PackageReference Include="xunit" Version="2.9.2" />
 		<PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
 		<PackageReference Include="coverlet.collector" Version="6.0.2" />