diff --git a/Chapter-1-initial-architecture/Src/Fitnet.ArchitectureTests/BussinessRulesArchitectureTests.cs b/Chapter-1-initial-architecture/Src/Fitnet.ArchitectureTests/BussinessRulesArchitectureTests.cs
new file mode 100644
index 00000000..e7ef173d
--- /dev/null
+++ b/Chapter-1-initial-architecture/Src/Fitnet.ArchitectureTests/BussinessRulesArchitectureTests.cs
@@ -0,0 +1,26 @@
+namespace EvolutionaryArchitecture.Fitnet.ArchitectureTests;
+
+using Common;
+using Fitnet.Common.BusinessRulesEngine;
+
+public class BusinessRulesArchitectureTests
+{
+    [Theory]
+    [InlineData("Endpoint")]
+    [InlineData("Consumer")]
+    internal void BusinessRules_Should_Not_Have_Dependency_On_Module(string forbiddenTypeEnding)
+    {
+        // Arrange
+        var businessRules = Solution.Types.That().ImplementInterface(typeof(IBusinessRule)).GetModuleTypes();
+        var forbiddenTypes = Solution
+            .Types
+            .That()
+            .HaveNameEndingWith(forbiddenTypeEnding);
+
+        // Act
+        var validationResult = forbiddenTypes!.Should().NotHaveDependencyOnAny(businessRules).GetResult();
+
+        // Assert
+        validationResult.FailingTypes.Should().BeNull();
+    }
+}
diff --git a/Chapter-1-initial-architecture/Src/Fitnet.ArchitectureTests/ContractsArchitectureTests.cs b/Chapter-1-initial-architecture/Src/Fitnet.ArchitectureTests/ContractsArchitectureTests.cs
index fa274605..745126f8 100644
--- a/Chapter-1-initial-architecture/Src/Fitnet.ArchitectureTests/ContractsArchitectureTests.cs
+++ b/Chapter-1-initial-architecture/Src/Fitnet.ArchitectureTests/ContractsArchitectureTests.cs
@@ -4,8 +4,6 @@
 
 public sealed class ContractsArchitectureTests
 {
-    private readonly Assembly _solution = typeof(Program).Assembly;
-
     [Theory]
     [InlineData(Modules.Passes)]
     [InlineData(Modules.Offers)]
@@ -13,11 +11,11 @@ public sealed class ContractsArchitectureTests
     internal void Contracts_should_not_have_dependency_on_module(string moduleName)
     {
         // Arrange
-        var contractsModule = Types.InAssembly(_solution)
+        var contractsModule = Solution.Types
             .That()
             .ResideInNamespace(Modules.Contracts);
 
-        var forbiddenModule = Types.InAssembly(_solution)
+        var forbiddenModule = Solution.Types
             .That()
             .ResideInNamespace(moduleName);
         var forbiddenModuleTypes = forbiddenModule.GetModuleTypes();
diff --git a/Chapter-1-initial-architecture/Src/Fitnet/Contracts/SignContract/SignContractEndpoint.cs b/Chapter-1-initial-architecture/Src/Fitnet/Contracts/SignContract/SignContractEndpoint.cs
index 3b53f5b4..84ed99ce 100644
--- a/Chapter-1-initial-architecture/Src/Fitnet/Contracts/SignContract/SignContractEndpoint.cs
+++ b/Chapter-1-initial-architecture/Src/Fitnet/Contracts/SignContract/SignContractEndpoint.cs
@@ -4,6 +4,7 @@ namespace EvolutionaryArchitecture.Fitnet.Contracts.SignContract;
 using Events;
 using EvolutionaryArchitecture.Fitnet.Common.Events.EventBus;
 using Common.Validation.Requests;
+using PrepareContract.BusinessRules;
 
 internal static class SignContractEndpoint
 {
@@ -14,6 +15,11 @@ internal static void MapSignContract(this IEndpointRouteBuilder app) => app.MapP
                 TimeProvider timeProvider,
                 CancellationToken cancellationToken) =>
             {
+                var test = new ContractCanBePreparedOnlyForAdultRule(10);
+#pragma warning disable S1481
+                var _ = test.Error;
+#pragma warning restore S1481
+
                 var contract =
                     await persistence.Contracts.FindAsync(new object[] { id }, cancellationToken: cancellationToken);
 
diff --git a/Chapter-1-initial-architecture/Src/Fitnet/Fitnet.csproj b/Chapter-1-initial-architecture/Src/Fitnet/Fitnet.csproj
index df162f68..6123cb1e 100644
--- a/Chapter-1-initial-architecture/Src/Fitnet/Fitnet.csproj
+++ b/Chapter-1-initial-architecture/Src/Fitnet/Fitnet.csproj
@@ -20,6 +20,7 @@
     <ItemGroup>
         <InternalsVisibleTo Include="EvolutionaryArchitecture.Fitnet.UnitTests" />
         <InternalsVisibleTo Include="EvolutionaryArchitecture.Fitnet.IntegrationTests" />
+        <InternalsVisibleTo Include="EvolutionaryArchitecture.Fitnet.ArchitectureTests" />
     </ItemGroup>
 
     <ItemGroup>
diff --git a/Chapter-2-modules-separation/Src/Reports/Fitnet.Reports/DataAccess/DatabaseConnectionFactory.cs b/Chapter-2-modules-separation/Src/Reports/Fitnet.Reports/DataAccess/DatabaseConnectionFactory.cs
index 3e786ab5..a10b770d 100644
--- a/Chapter-2-modules-separation/Src/Reports/Fitnet.Reports/DataAccess/DatabaseConnectionFactory.cs
+++ b/Chapter-2-modules-separation/Src/Reports/Fitnet.Reports/DataAccess/DatabaseConnectionFactory.cs
@@ -2,6 +2,7 @@ namespace EvolutionaryArchitecture.Fitnet.Reports.DataAccess;
 
 using Microsoft.Extensions.Configuration;
 using System.Data;
+using System.Diagnostics.CodeAnalysis;
 using Npgsql;
 
 internal sealed class DatabaseConnectionFactory(IConfiguration configuration) : IDatabaseConnectionFactory
@@ -22,6 +23,7 @@ public IDbConnection Create()
         return _connection;
     }
 
+    [ExcludeFromCodeCoverage]
     public void Dispose()
     {
         if (_connection is { State: ConnectionState.Open })