diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
index 1d47c0b4e9bf..78155a74ea09 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java
@@ -604,7 +604,7 @@ public CodegenModel fromModel(String name, Schema model) {
                 }
 
                 for (final CodegenProperty property : codegenModel.readWriteVars) {
-                    if (property.defaultValue == null && parentCodegenModel.discriminator != null && property.baseName.equals(parentCodegenModel.discriminator.getPropertyName())) {
+                    if (property.defaultValue == null && parentCodegenModel.discriminator != null && property.name.equals(parentCodegenModel.discriminator.getPropertyName())) {
                         property.defaultValue = "\"" + name + "\"";
                     }
                 }
diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java
index 0e189813db70..c97787acddf9 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpNetCoreClientCodegen.java
@@ -299,7 +299,7 @@ public CodegenModel fromModel(String name, Schema model) {
                 }
 
                 for (final CodegenProperty property : codegenModel.readWriteVars) {
-                    if (property.defaultValue == null && parentCodegenModel.discriminator != null && property.baseName.equals(parentCodegenModel.discriminator.getPropertyName())) {
+                    if (property.defaultValue == null && parentCodegenModel.discriminator != null && property.name.equals(parentCodegenModel.discriminator.getPropertyName())) {
                         property.defaultValue = "\"" + name + "\"";
                     }
                 }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
index 1633be4289c7..36301ec6388d 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
@@ -40,9 +40,9 @@ protected Cat() { }
         /// Initializes a new instance of the <see cref="Cat" /> class.
         /// </summary>
         /// <param name="declawed">declawed.</param>
-        /// <param name="className">className (required).</param>
+        /// <param name="className">className (required) (default to &quot;Cat&quot;).</param>
         /// <param name="color">color (default to &quot;red&quot;).</param>
-        public Cat(bool declawed = default(bool), string className = default(string), string color = "red") : base(className, color)
+        public Cat(bool declawed = default(bool), string className = "Cat", string color = "red") : base(className, color)
         {
             this.Declawed = declawed;
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
index 509bd8813c13..15b7a28ef1a4 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
@@ -40,9 +40,9 @@ protected Dog() { }
         /// Initializes a new instance of the <see cref="Dog" /> class.
         /// </summary>
         /// <param name="breed">breed.</param>
-        /// <param name="className">className (required).</param>
+        /// <param name="className">className (required) (default to &quot;Dog&quot;).</param>
         /// <param name="color">color (default to &quot;red&quot;).</param>
-        public Dog(string breed = default(string), string className = default(string), string color = "red") : base(className, color)
+        public Dog(string breed = default(string), string className = "Dog", string color = "red") : base(className, color)
         {
             this.Breed = breed;
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Cat.cs b/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Cat.cs
index 1633be4289c7..36301ec6388d 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Cat.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Cat.cs
@@ -40,9 +40,9 @@ protected Cat() { }
         /// Initializes a new instance of the <see cref="Cat" /> class.
         /// </summary>
         /// <param name="declawed">declawed.</param>
-        /// <param name="className">className (required).</param>
+        /// <param name="className">className (required) (default to &quot;Cat&quot;).</param>
         /// <param name="color">color (default to &quot;red&quot;).</param>
-        public Cat(bool declawed = default(bool), string className = default(string), string color = "red") : base(className, color)
+        public Cat(bool declawed = default(bool), string className = "Cat", string color = "red") : base(className, color)
         {
             this.Declawed = declawed;
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Dog.cs b/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Dog.cs
index 509bd8813c13..15b7a28ef1a4 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Dog.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/Dog.cs
@@ -40,9 +40,9 @@ protected Dog() { }
         /// Initializes a new instance of the <see cref="Dog" /> class.
         /// </summary>
         /// <param name="breed">breed.</param>
-        /// <param name="className">className (required).</param>
+        /// <param name="className">className (required) (default to &quot;Dog&quot;).</param>
         /// <param name="color">color (default to &quot;red&quot;).</param>
-        public Dog(string breed = default(string), string className = default(string), string color = "red") : base(className, color)
+        public Dog(string breed = default(string), string className = "Dog", string color = "red") : base(className, color)
         {
             this.Breed = breed;
         }
diff --git a/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/ParentPet.cs b/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/ParentPet.cs
index 1ac128d23105..05d8a67ce611 100644
--- a/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/ParentPet.cs
+++ b/samples/client/petstore/csharp-netcore/OpenAPIClientCore/src/Org.OpenAPITools/Model/ParentPet.cs
@@ -39,8 +39,8 @@ protected ParentPet() { }
         /// <summary>
         /// Initializes a new instance of the <see cref="ParentPet" /> class.
         /// </summary>
-        /// <param name="petType">petType (required).</param>
-        public ParentPet(string petType = default(string)) : base(petType)
+        /// <param name="petType">petType (required) (default to &quot;ParentPet&quot;).</param>
+        public ParentPet(string petType = "ParentPet") : base(petType)
         {
         }
 
diff --git a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
index 1c28fb2755f7..e4cfa3fbef4d 100644
--- a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Cat.cs
@@ -39,7 +39,7 @@ protected Cat() { }
         /// Initializes a new instance of the <see cref="Cat" /> class.
         /// </summary>
         /// <param name="declawed">declawed.</param>
-        public Cat(bool declawed = default(bool), string className = default(string), string color = "red") : base(className, color)
+        public Cat(bool declawed = default(bool), string className = "Cat", string color = "red") : base(className, color)
         {
             this.Declawed = declawed;
         }
diff --git a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
index 96e568628fe5..b925fb99c324 100644
--- a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Dog.cs
@@ -39,7 +39,7 @@ protected Dog() { }
         /// Initializes a new instance of the <see cref="Dog" /> class.
         /// </summary>
         /// <param name="breed">breed.</param>
-        public Dog(string breed = default(string), string className = default(string), string color = "red") : base(className, color)
+        public Dog(string breed = default(string), string className = "Dog", string color = "red") : base(className, color)
         {
             this.Breed = breed;
         }