diff --git a/internal/cmd/testdata/success_csharp.golden b/internal/cmd/testdata/success_csharp.golden
index 05fa1d0..a77ce09 100644
--- a/internal/cmd/testdata/success_csharp.golden
+++ b/internal/cmd/testdata/success_csharp.golden
@@ -41,7 +41,7 @@ namespace TestNamespace
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient())
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient())
                 .AddSingleton<GeneratedClient>();
         }
 
@@ -55,7 +55,7 @@ namespace TestNamespace
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient(domain))
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient(domain))
                 .AddSingleton<GeneratedClient>();
         }
     }
diff --git a/internal/generators/csharp/csharp.tmpl b/internal/generators/csharp/csharp.tmpl
index 414e434..f09bf64 100644
--- a/internal/generators/csharp/csharp.tmpl
+++ b/internal/generators/csharp/csharp.tmpl
@@ -35,7 +35,7 @@ namespace {{ if .Params.Custom.Namespace }}{{ .Params.Custom.Namespace }}{{ else
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient())
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient())
                 .AddSingleton<GeneratedClient>();
         }
 
@@ -49,7 +49,7 @@ namespace {{ if .Params.Custom.Namespace }}{{ .Params.Custom.Namespace }}{{ else
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient(domain))
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient(domain))
                 .AddSingleton<GeneratedClient>();
         }
     }
diff --git a/test/csharp-integration/OpenFeature.g.cs b/test/csharp-integration/OpenFeature.g.cs
index 05fa1d0..a77ce09 100644
--- a/test/csharp-integration/OpenFeature.g.cs
+++ b/test/csharp-integration/OpenFeature.g.cs
@@ -41,7 +41,7 @@ public static IServiceCollection AddOpenFeature(this IServiceCollection services
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient())
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient())
                 .AddSingleton<GeneratedClient>();
         }
 
@@ -55,7 +55,7 @@ public static IServiceCollection AddOpenFeature(this IServiceCollection services
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient(domain))
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient(domain))
                 .AddSingleton<GeneratedClient>();
         }
     }
diff --git a/test/csharp-integration/Program.cs b/test/csharp-integration/Program.cs
index 03bd66d..3c3230b 100644
--- a/test/csharp-integration/Program.cs
+++ b/test/csharp-integration/Program.cs
@@ -17,10 +17,9 @@ static void Main(string[] args)
             
             // Test DI initialization
             var services = new ServiceCollection();
-            // Register OpenFeature services manually for the test
-            services.AddSingleton(_ => Api.Instance);
-            services.AddSingleton<IFeatureClient>(_ => Api.Instance.GetClient());
-            services.AddSingleton<GeneratedClient>();
+            
+            services.AddOpenFeature();
+
             var serviceProvider = services.BuildServiceProvider();
             
             // Test client retrieval from DI
diff --git a/test/csharp-integration/expected/OpenFeature.cs b/test/csharp-integration/expected/OpenFeature.cs
index cd0f584..c814fcf 100644
--- a/test/csharp-integration/expected/OpenFeature.cs
+++ b/test/csharp-integration/expected/OpenFeature.cs
@@ -25,7 +25,7 @@ public static IServiceCollection AddOpenFeature(this IServiceCollection services
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient())
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient())
                 .AddSingleton<GeneratedClient>();
         }
 
@@ -39,7 +39,7 @@ public static IServiceCollection AddOpenFeature(this IServiceCollection services
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient(domain))
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient(domain))
                 .AddSingleton<GeneratedClient>();
         }
     }
diff --git a/test/csharp-integration/expected/OpenFeature.g.cs b/test/csharp-integration/expected/OpenFeature.g.cs
index a9ed769..835ebf9 100644
--- a/test/csharp-integration/expected/OpenFeature.g.cs
+++ b/test/csharp-integration/expected/OpenFeature.g.cs
@@ -24,7 +24,7 @@ public static IServiceCollection AddOpenFeature(this IServiceCollection services
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient())
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient())
                 .AddSingleton<GeneratedClient>();
         }
 
@@ -38,7 +38,7 @@ public static IServiceCollection AddOpenFeature(this IServiceCollection services
         {
             return services
                 .AddSingleton(_ => Api.Instance)
-                .AddSingleton(provider => provider.GetRequiredService<Api>().GetClient(domain))
+                .AddSingleton<IFeatureClient, FeatureClient>(provider => provider.GetRequiredService<Api>().GetClient(domain))
                 .AddSingleton<GeneratedClient>();
         }
     }