diff --git a/modules/openapi-generator/src/main/resources/aspnetcore/2.0/model.mustache b/modules/openapi-generator/src/main/resources/aspnetcore/2.0/model.mustache
index 18355dadb3d..670e24f4136 100644
--- a/modules/openapi-generator/src/main/resources/aspnetcore/2.0/model.mustache
+++ b/modules/openapi-generator/src/main/resources/aspnetcore/2.0/model.mustache
@@ -26,7 +26,7 @@ namespace {{packageName}}.Models
         {{#required}}
         [Required]
         {{/required}}
-        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#isNullable}}true{{/isNullable}}{{^isNullable}}{{emitDefaultValue}}{{/isNullable}})]
+        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}})]
         {{#isEnum}}
         public {{{datatypeWithEnum}}}{{#isEnum}}{{^isContainer}}?{{/isContainer}}{{/isEnum}} {{name}} { get; set; }
         {{/isEnum}}
diff --git a/modules/openapi-generator/src/main/resources/aspnetcore/2.1/model.mustache b/modules/openapi-generator/src/main/resources/aspnetcore/2.1/model.mustache
index 18355dadb3d..670e24f4136 100644
--- a/modules/openapi-generator/src/main/resources/aspnetcore/2.1/model.mustache
+++ b/modules/openapi-generator/src/main/resources/aspnetcore/2.1/model.mustache
@@ -26,7 +26,7 @@ namespace {{packageName}}.Models
         {{#required}}
         [Required]
         {{/required}}
-        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#isNullable}}true{{/isNullable}}{{^isNullable}}{{emitDefaultValue}}{{/isNullable}})]
+        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}})]
         {{#isEnum}}
         public {{{datatypeWithEnum}}}{{#isEnum}}{{^isContainer}}?{{/isContainer}}{{/isEnum}} {{name}} { get; set; }
         {{/isEnum}}
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/PetApi.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/PetApi.cs
index bf921975337..8a0d855e30f 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/PetApi.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/PetApi.cs
@@ -83,7 +83,7 @@ namespace Org.OpenAPITools.Controllers
             // return StatusCode(400);
 
             string exampleJson = null;
-            exampleJson = "{\r\n  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],\r\n  \"name\" : \"doggie\",\r\n  \"id\" : 0,\r\n  \"category\" : {\r\n    \"name\" : \"name\",\r\n    \"id\" : 6\r\n  },\r\n  \"tags\" : [ {\r\n    \"name\" : \"name\",\r\n    \"id\" : 1\r\n  }, {\r\n    \"name\" : \"name\",\r\n    \"id\" : 1\r\n  } ],\r\n  \"status\" : \"available\"\r\n}";
+            exampleJson = "{\n  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],\n  \"name\" : \"doggie\",\n  \"id\" : 0,\n  \"category\" : {\n    \"name\" : \"name\",\n    \"id\" : 6\n  },\n  \"tags\" : [ {\n    \"name\" : \"name\",\n    \"id\" : 1\n  }, {\n    \"name\" : \"name\",\n    \"id\" : 1\n  } ],\n  \"status\" : \"available\"\n}";
             exampleJson = "<Pet>\n  <id>123456789</id>\n  <name>doggie</name>\n  <photoUrls>\n    <photoUrls>aeiou</photoUrls>\n  </photoUrls>\n  <tags>\n  </tags>\n  <status>aeiou</status>\n</Pet>";
             
             var example = exampleJson != null
@@ -114,7 +114,7 @@ namespace Org.OpenAPITools.Controllers
             // return StatusCode(400);
 
             string exampleJson = null;
-            exampleJson = "{\r\n  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],\r\n  \"name\" : \"doggie\",\r\n  \"id\" : 0,\r\n  \"category\" : {\r\n    \"name\" : \"name\",\r\n    \"id\" : 6\r\n  },\r\n  \"tags\" : [ {\r\n    \"name\" : \"name\",\r\n    \"id\" : 1\r\n  }, {\r\n    \"name\" : \"name\",\r\n    \"id\" : 1\r\n  } ],\r\n  \"status\" : \"available\"\r\n}";
+            exampleJson = "{\n  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],\n  \"name\" : \"doggie\",\n  \"id\" : 0,\n  \"category\" : {\n    \"name\" : \"name\",\n    \"id\" : 6\n  },\n  \"tags\" : [ {\n    \"name\" : \"name\",\n    \"id\" : 1\n  }, {\n    \"name\" : \"name\",\n    \"id\" : 1\n  } ],\n  \"status\" : \"available\"\n}";
             exampleJson = "<Pet>\n  <id>123456789</id>\n  <name>doggie</name>\n  <photoUrls>\n    <photoUrls>aeiou</photoUrls>\n  </photoUrls>\n  <tags>\n  </tags>\n  <status>aeiou</status>\n</Pet>";
             
             var example = exampleJson != null
@@ -149,7 +149,7 @@ namespace Org.OpenAPITools.Controllers
             // return StatusCode(404);
 
             string exampleJson = null;
-            exampleJson = "{\r\n  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],\r\n  \"name\" : \"doggie\",\r\n  \"id\" : 0,\r\n  \"category\" : {\r\n    \"name\" : \"name\",\r\n    \"id\" : 6\r\n  },\r\n  \"tags\" : [ {\r\n    \"name\" : \"name\",\r\n    \"id\" : 1\r\n  }, {\r\n    \"name\" : \"name\",\r\n    \"id\" : 1\r\n  } ],\r\n  \"status\" : \"available\"\r\n}";
+            exampleJson = "{\n  \"photoUrls\" : [ \"photoUrls\", \"photoUrls\" ],\n  \"name\" : \"doggie\",\n  \"id\" : 0,\n  \"category\" : {\n    \"name\" : \"name\",\n    \"id\" : 6\n  },\n  \"tags\" : [ {\n    \"name\" : \"name\",\n    \"id\" : 1\n  }, {\n    \"name\" : \"name\",\n    \"id\" : 1\n  } ],\n  \"status\" : \"available\"\n}";
             exampleJson = "<Pet>\n  <id>123456789</id>\n  <name>doggie</name>\n  <photoUrls>\n    <photoUrls>aeiou</photoUrls>\n  </photoUrls>\n  <tags>\n  </tags>\n  <status>aeiou</status>\n</Pet>";
             
             var example = exampleJson != null
@@ -223,7 +223,7 @@ namespace Org.OpenAPITools.Controllers
             // return StatusCode(200, default(ApiResponse));
 
             string exampleJson = null;
-            exampleJson = "{\r\n  \"code\" : 0,\r\n  \"type\" : \"type\",\r\n  \"message\" : \"message\"\r\n}";
+            exampleJson = "{\n  \"code\" : 0,\n  \"type\" : \"type\",\n  \"message\" : \"message\"\n}";
             
             var example = exampleJson != null
             ? JsonConvert.DeserializeObject<ApiResponse>(exampleJson)
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/StoreApi.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/StoreApi.cs
index 3a7724d05fa..d6e4720d4c1 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/StoreApi.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/StoreApi.cs
@@ -97,7 +97,7 @@ namespace Org.OpenAPITools.Controllers
             // return StatusCode(404);
 
             string exampleJson = null;
-            exampleJson = "{\r\n  \"petId\" : 6,\r\n  \"quantity\" : 1,\r\n  \"id\" : 0,\r\n  \"shipDate\" : \"2000-01-23T04:56:07.000+00:00\",\r\n  \"complete\" : false,\r\n  \"status\" : \"placed\"\r\n}";
+            exampleJson = "{\n  \"petId\" : 6,\n  \"quantity\" : 1,\n  \"id\" : 0,\n  \"shipDate\" : \"2000-01-23T04:56:07.000+00:00\",\n  \"complete\" : false,\n  \"status\" : \"placed\"\n}";
             exampleJson = "<Order>\n  <id>123456789</id>\n  <petId>123456789</petId>\n  <quantity>123</quantity>\n  <shipDate>2000-01-23T04:56:07.000Z</shipDate>\n  <status>aeiou</status>\n  <complete>true</complete>\n</Order>";
             
             var example = exampleJson != null
@@ -127,7 +127,7 @@ namespace Org.OpenAPITools.Controllers
             // return StatusCode(400);
 
             string exampleJson = null;
-            exampleJson = "{\r\n  \"petId\" : 6,\r\n  \"quantity\" : 1,\r\n  \"id\" : 0,\r\n  \"shipDate\" : \"2000-01-23T04:56:07.000+00:00\",\r\n  \"complete\" : false,\r\n  \"status\" : \"placed\"\r\n}";
+            exampleJson = "{\n  \"petId\" : 6,\n  \"quantity\" : 1,\n  \"id\" : 0,\n  \"shipDate\" : \"2000-01-23T04:56:07.000+00:00\",\n  \"complete\" : false,\n  \"status\" : \"placed\"\n}";
             exampleJson = "<Order>\n  <id>123456789</id>\n  <petId>123456789</petId>\n  <quantity>123</quantity>\n  <shipDate>2000-01-23T04:56:07.000Z</shipDate>\n  <status>aeiou</status>\n  <complete>true</complete>\n</Order>";
             
             var example = exampleJson != null
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/UserApi.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/UserApi.cs
index 913be703891..01f3ade7a5b 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/UserApi.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Controllers/UserApi.cs
@@ -127,7 +127,7 @@ namespace Org.OpenAPITools.Controllers
             // return StatusCode(404);
 
             string exampleJson = null;
-            exampleJson = "{\r\n  \"firstName\" : \"firstName\",\r\n  \"lastName\" : \"lastName\",\r\n  \"password\" : \"password\",\r\n  \"userStatus\" : 6,\r\n  \"phone\" : \"phone\",\r\n  \"id\" : 0,\r\n  \"email\" : \"email\",\r\n  \"username\" : \"username\"\r\n}";
+            exampleJson = "{\n  \"firstName\" : \"firstName\",\n  \"lastName\" : \"lastName\",\n  \"password\" : \"password\",\n  \"userStatus\" : 6,\n  \"phone\" : \"phone\",\n  \"id\" : 0,\n  \"email\" : \"email\",\n  \"username\" : \"username\"\n}";
             exampleJson = "<User>\n  <id>123456789</id>\n  <username>aeiou</username>\n  <firstName>aeiou</firstName>\n  <lastName>aeiou</lastName>\n  <email>aeiou</email>\n  <password>aeiou</password>\n  <phone>aeiou</phone>\n  <userStatus>123</userStatus>\n</User>";
             
             var example = exampleJson != null
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/ApiResponse.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/ApiResponse.cs
index d5ddd110bd9..363087cfd97 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/ApiResponse.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/ApiResponse.cs
@@ -27,19 +27,19 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Code
         /// </summary>
-        [DataMember(Name="code")]
+        [DataMember(Name="code", EmitDefaultValue=false)]
         public int? Code { get; set; }
 
         /// <summary>
         /// Gets or Sets Type
         /// </summary>
-        [DataMember(Name="type")]
+        [DataMember(Name="type", EmitDefaultValue=false)]
         public string Type { get; set; }
 
         /// <summary>
         /// Gets or Sets Message
         /// </summary>
-        [DataMember(Name="message")]
+        [DataMember(Name="message", EmitDefaultValue=false)]
         public string Message { get; set; }
 
         /// <summary>
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Category.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Category.cs
index 44b87698f26..aafdde5db73 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Category.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Category.cs
@@ -27,13 +27,13 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Id
         /// </summary>
-        [DataMember(Name="id")]
+        [DataMember(Name="id", EmitDefaultValue=false)]
         public long? Id { get; set; }
 
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
-        [DataMember(Name="name")]
+        [DataMember(Name="name", EmitDefaultValue=false)]
         public string Name { get; set; }
 
         /// <summary>
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Order.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Order.cs
index 673983d6bce..8abf9f9c492 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Order.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Order.cs
@@ -27,25 +27,25 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Id
         /// </summary>
-        [DataMember(Name="id")]
+        [DataMember(Name="id", EmitDefaultValue=false)]
         public long? Id { get; set; }
 
         /// <summary>
         /// Gets or Sets PetId
         /// </summary>
-        [DataMember(Name="petId")]
+        [DataMember(Name="petId", EmitDefaultValue=false)]
         public long? PetId { get; set; }
 
         /// <summary>
         /// Gets or Sets Quantity
         /// </summary>
-        [DataMember(Name="quantity")]
+        [DataMember(Name="quantity", EmitDefaultValue=false)]
         public int? Quantity { get; set; }
 
         /// <summary>
         /// Gets or Sets ShipDate
         /// </summary>
-        [DataMember(Name="shipDate")]
+        [DataMember(Name="shipDate", EmitDefaultValue=false)]
         public DateTime? ShipDate { get; set; }
 
         /// <summary>
@@ -79,13 +79,13 @@ namespace Org.OpenAPITools.Models
         /// Order Status
         /// </summary>
         /// <value>Order Status</value>
-        [DataMember(Name="status")]
+        [DataMember(Name="status", EmitDefaultValue=false)]
         public StatusEnum? Status { get; set; }
 
         /// <summary>
         /// Gets or Sets Complete
         /// </summary>
-        [DataMember(Name="complete")]
+        [DataMember(Name="complete", EmitDefaultValue=false)]
         public bool? Complete { get; set; }
 
         /// <summary>
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Pet.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Pet.cs
index 927a9087b49..ddb23c6d92b 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Pet.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Pet.cs
@@ -27,33 +27,33 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Id
         /// </summary>
-        [DataMember(Name="id")]
+        [DataMember(Name="id", EmitDefaultValue=false)]
         public long? Id { get; set; }
 
         /// <summary>
         /// Gets or Sets Category
         /// </summary>
-        [DataMember(Name="category")]
+        [DataMember(Name="category", EmitDefaultValue=false)]
         public Category Category { get; set; }
 
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
         [Required]
-        [DataMember(Name="name")]
+        [DataMember(Name="name", EmitDefaultValue=false)]
         public string Name { get; set; }
 
         /// <summary>
         /// Gets or Sets PhotoUrls
         /// </summary>
         [Required]
-        [DataMember(Name="photoUrls")]
+        [DataMember(Name="photoUrls", EmitDefaultValue=false)]
         public List<string> PhotoUrls { get; set; }
 
         /// <summary>
         /// Gets or Sets Tags
         /// </summary>
-        [DataMember(Name="tags")]
+        [DataMember(Name="tags", EmitDefaultValue=false)]
         public List<Tag> Tags { get; set; }
 
         /// <summary>
@@ -87,7 +87,7 @@ namespace Org.OpenAPITools.Models
         /// pet status in the store
         /// </summary>
         /// <value>pet status in the store</value>
-        [DataMember(Name="status")]
+        [DataMember(Name="status", EmitDefaultValue=false)]
         public StatusEnum? Status { get; set; }
 
         /// <summary>
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Tag.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Tag.cs
index f3f652c0e4e..9750103a894 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Tag.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/Tag.cs
@@ -27,13 +27,13 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Id
         /// </summary>
-        [DataMember(Name="id")]
+        [DataMember(Name="id", EmitDefaultValue=false)]
         public long? Id { get; set; }
 
         /// <summary>
         /// Gets or Sets Name
         /// </summary>
-        [DataMember(Name="name")]
+        [DataMember(Name="name", EmitDefaultValue=false)]
         public string Name { get; set; }
 
         /// <summary>
diff --git a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/User.cs b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/User.cs
index df458f9bbd2..6e5c3f7ca73 100644
--- a/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/User.cs
+++ b/samples/server/petstore/aspnetcore/src/Org.OpenAPITools/Models/User.cs
@@ -27,50 +27,50 @@ namespace Org.OpenAPITools.Models
         /// <summary>
         /// Gets or Sets Id
         /// </summary>
-        [DataMember(Name="id")]
+        [DataMember(Name="id", EmitDefaultValue=false)]
         public long? Id { get; set; }
 
         /// <summary>
         /// Gets or Sets Username
         /// </summary>
-        [DataMember(Name="username")]
+        [DataMember(Name="username", EmitDefaultValue=false)]
         public string Username { get; set; }
 
         /// <summary>
         /// Gets or Sets FirstName
         /// </summary>
-        [DataMember(Name="firstName")]
+        [DataMember(Name="firstName", EmitDefaultValue=false)]
         public string FirstName { get; set; }
 
         /// <summary>
         /// Gets or Sets LastName
         /// </summary>
-        [DataMember(Name="lastName")]
+        [DataMember(Name="lastName", EmitDefaultValue=false)]
         public string LastName { get; set; }
 
         /// <summary>
         /// Gets or Sets Email
         /// </summary>
-        [DataMember(Name="email")]
+        [DataMember(Name="email", EmitDefaultValue=false)]
         public string Email { get; set; }
 
         /// <summary>
         /// Gets or Sets Password
         /// </summary>
-        [DataMember(Name="password")]
+        [DataMember(Name="password", EmitDefaultValue=false)]
         public string Password { get; set; }
 
         /// <summary>
         /// Gets or Sets Phone
         /// </summary>
-        [DataMember(Name="phone")]
+        [DataMember(Name="phone", EmitDefaultValue=false)]
         public string Phone { get; set; }
 
         /// <summary>
         /// User Status
         /// </summary>
         /// <value>User Status</value>
-        [DataMember(Name="userStatus")]
+        [DataMember(Name="userStatus", EmitDefaultValue=false)]
         public int? UserStatus { get; set; }
 
         /// <summary>