diff --git a/src/NSwag.CodeGeneration.CSharp.Tests/CSharpClientSettingsTests.cs b/src/NSwag.CodeGeneration.CSharp.Tests/CSharpClientSettingsTests.cs
index 05350c01f..b859c1bca 100644
--- a/src/NSwag.CodeGeneration.CSharp.Tests/CSharpClientSettingsTests.cs
+++ b/src/NSwag.CodeGeneration.CSharp.Tests/CSharpClientSettingsTests.cs
@@ -175,6 +175,29 @@ public async Task When_client_base_interface_is_not_specified_then_client_interf
             Assert.Contains("public partial interface IFooClient\n", code);
         }
 
+        [Fact]
+        public async Task When_client_base_interface_is_not_specified_then_client_interface_should_have_no_base_interface_and_has_correct_access_modifier()
+        {
+            // Arrange
+            var swaggerGenerator = new WebApiOpenApiDocumentGenerator(new WebApiOpenApiDocumentGeneratorSettings
+            {
+                SchemaSettings = new NewtonsoftJsonSchemaGeneratorSettings()
+            });
+
+            var document = await swaggerGenerator.GenerateForControllerAsync<FooController>();
+            var generator = new CSharpClientGenerator(document, new CSharpClientGeneratorSettings
+            {
+                GenerateClientInterfaces = true,
+                ClientInterfaceAccessModifier = "internal"
+            });
+
+            // Act
+            var code = generator.GenerateFile();
+
+            // Assert
+            Assert.Contains("internal partial interface IFooClient\n", code);
+        }
+
         [Fact]
         public async Task When_client_base_interface_is_specified_then_client_interface_extends_it()
         {
@@ -198,6 +221,30 @@ public async Task When_client_base_interface_is_specified_then_client_interface_
             Assert.Contains("public partial interface IFooClient : IClientBase", code);
         }
 
+        [Fact]
+        public async Task When_client_base_interface_is_specified_with_access_modifier_then_client_interface_extends_it_and_has_correct_access_modifier()
+        {
+            // Arrange
+            var swaggerGenerator = new WebApiOpenApiDocumentGenerator(new WebApiOpenApiDocumentGeneratorSettings
+            {
+                SchemaSettings = new NewtonsoftJsonSchemaGeneratorSettings()
+            });
+
+            var document = await swaggerGenerator.GenerateForControllerAsync<FooController>();
+            var generator = new CSharpClientGenerator(document, new CSharpClientGeneratorSettings
+            {
+                GenerateClientInterfaces = true,
+                ClientBaseInterface = "IClientBase",
+                ClientInterfaceAccessModifier = "internal"
+            });
+
+            // Act
+            var code = generator.GenerateFile();
+
+            // Assert
+            Assert.Contains("internal partial interface IFooClient : IClientBase", code);
+        }
+
         [Fact]
         public async Task When_client_class_generation_is_enabled_and_suppressed_then_client_class_is_not_generated()
         {
diff --git a/src/NSwag.CodeGeneration.CSharp/CSharpClientGeneratorSettings.cs b/src/NSwag.CodeGeneration.CSharp/CSharpClientGeneratorSettings.cs
index efe684aa9..cbe18c2c2 100644
--- a/src/NSwag.CodeGeneration.CSharp/CSharpClientGeneratorSettings.cs
+++ b/src/NSwag.CodeGeneration.CSharp/CSharpClientGeneratorSettings.cs
@@ -19,6 +19,7 @@ public CSharpClientGeneratorSettings()
             GenerateExceptionClasses = true;
             ExceptionClass = "ApiException";
             ClientClassAccessModifier = "public";
+            ClientInterfaceAccessModifier = "public";
             UseBaseUrl = true;
             HttpClientType = "System.Net.Http.HttpClient";
             WrapDtoExceptions = true;
@@ -70,6 +71,9 @@ public CSharpClientGeneratorSettings()
         /// <summary>Gets or sets the client class access modifier (default: public).</summary>
         public string ClientClassAccessModifier { get; set; }
 
+        /// <summary>Gets or sets the client interface access modifier (default: public).</summary>
+        public string ClientInterfaceAccessModifier { get; set; }
+
         /// <summary>Gets or sets a value indicating whether to use and expose the base URL (default: true).</summary>
         public bool UseBaseUrl { get; set; }
 
diff --git a/src/NSwag.CodeGeneration.CSharp/Models/CSharpClientTemplateModel.cs b/src/NSwag.CodeGeneration.CSharp/Models/CSharpClientTemplateModel.cs
index e73787d16..37eb12e2e 100644
--- a/src/NSwag.CodeGeneration.CSharp/Models/CSharpClientTemplateModel.cs
+++ b/src/NSwag.CodeGeneration.CSharp/Models/CSharpClientTemplateModel.cs
@@ -122,6 +122,9 @@ public CSharpClientTemplateModel(
         /// <summary>Gets or sets the client class access modifier.</summary>
         public string ClientClassAccessModifier => _settings.ClientClassAccessModifier;
 
+        /// <summary>Gets or sets the client interface access modifier.</summary>
+        public string ClientInterfaceAccessModifier => _settings.ClientInterfaceAccessModifier;
+
         /// <summary>Gets the operations.</summary>
         public IEnumerable<CSharpOperationModel> Operations { get; }
 
diff --git a/src/NSwag.CodeGeneration.CSharp/Templates/Client.Interface.liquid b/src/NSwag.CodeGeneration.CSharp/Templates/Client.Interface.liquid
index 8fbb51e45..c1d63ef4d 100644
--- a/src/NSwag.CodeGeneration.CSharp/Templates/Client.Interface.liquid
+++ b/src/NSwag.CodeGeneration.CSharp/Templates/Client.Interface.liquid
@@ -1,6 +1,6 @@
 {% template Client.Interface.Annotations %}
 [System.CodeDom.Compiler.GeneratedCode("NSwag", "{{ ToolchainVersion }}")]
-public partial interface I{{ Class }}{% if HasClientBaseInterface %} : {{ ClientBaseInterface }}{% endif %}
+{{ ClientInterfaceAccessModifier }} partial interface I{{ Class }}{% if HasClientBaseInterface %} : {{ ClientBaseInterface }}{% endif %}
 {
     {% template Client.Interface.Body %}
 {% for operation in InterfaceOperations -%}
diff --git a/src/NSwag.Commands/Commands/CodeGeneration/OpenApiToCSharpClientCommand.cs b/src/NSwag.Commands/Commands/CodeGeneration/OpenApiToCSharpClientCommand.cs
index fcb02cd5b..ee6781ef4 100644
--- a/src/NSwag.Commands/Commands/CodeGeneration/OpenApiToCSharpClientCommand.cs
+++ b/src/NSwag.Commands/Commands/CodeGeneration/OpenApiToCSharpClientCommand.cs
@@ -185,11 +185,16 @@ public string ClientClassAccessModifier
             set { Settings.ClientClassAccessModifier = value; }
         }
 
+
         [Argument(Name = "TypeAccessModifier", IsRequired = false, Description = "The DTO class/enum access modifier (default: public).")]
         public string TypeAccessModifier
         {
             get { return Settings.CSharpGeneratorSettings.TypeAccessModifier; }
-            set { Settings.CSharpGeneratorSettings.TypeAccessModifier = value; }
+            set
+            { 
+                Settings.CSharpGeneratorSettings.TypeAccessModifier = value;
+                Settings.ClientInterfaceAccessModifier = value;
+            }
         }
 
         [Argument(Name = "PropertySetterAccessModifier", IsRequired = false, Description = "The access modifier of property setters (default: '').")]