diff --git a/modules/openapi-generator/src/main/resources/swift4/api.mustache b/modules/openapi-generator/src/main/resources/swift4/api.mustache
index ed4afe13a0ff..6e9b01c3cad6 100644
--- a/modules/openapi-generator/src/main/resources/swift4/api.mustache
+++ b/modules/openapi-generator/src/main/resources/swift4/api.mustache
@@ -16,7 +16,7 @@ extension {{projectName}}API {
 
 {{#description}}
 /** {{description}} */{{/description}}
-open class {{classname}} {
+{{#objcCompatible}}@objc {{/objcCompatible}}open class {{classname}}{{#objcCompatible}} : NSObject{{/objcCompatible}} {
 {{#operation}}
     {{#allParams}}
     {{#isEnum}}
@@ -40,17 +40,22 @@ open class {{classname}} {
      - parameter {{paramName}}: ({{#isFormParam}}form{{/isFormParam}}{{#isQueryParam}}query{{/isQueryParam}}{{#isPathParam}}path{{/isPathParam}}{{#isHeaderParam}}header{{/isHeaderParam}}{{#isBodyParam}}body{{/isBodyParam}}) {{description}} {{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}{{/allParams}}
      - parameter completion: completion handler to receive the data and the error objects
      */
-    open class func {{operationId}}({{#allParams}}{{paramName}}: {{#isEnum}}{{#isContainer}}{{{dataType}}}{{/isContainer}}{{^isContainer}}{{{datatypeWithEnum}}}_{{operationId}}{{/isContainer}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{^required}}? = nil{{/required}}{{#hasMore}}, {{/hasMore}}{{/allParams}}{{#hasParams}}, {{/hasParams}}completion: @escaping ((_ data: {{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Void{{/returnType}}?,_ error: Error?) -> Void)) {
+    {{#objcCompatible}}@objc {{/objcCompatible}}open class func {{operationId}}({{#allParams}}{{paramName}}: {{#isEnum}}{{#isContainer}}{{{dataType}}}{{/isContainer}}{{^isContainer}}{{{datatypeWithEnum}}}_{{operationId}}{{/isContainer}}{{/isEnum}}{{^isEnum}}{{{dataType}}}{{/isEnum}}{{^required}}? = nil{{/required}}{{#hasMore}}, {{/hasMore}}{{/allParams}}{{#hasParams}}, {{/hasParams}}completion: @escaping (({{#returnType}}_ data: {{{returnType}}}?,{{/returnType}}{{^returnType}}{{^objcCompatible}}_ data: Void?,{{/objcCompatible}}{{/returnType}}_ error: Error?) -> Void)) {
         {{operationId}}WithRequestBuilder({{#allParams}}{{paramName}}: {{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}}).execute { (response, error) -> Void in
         {{#returnType}}
             completion(response?.body, error)
         {{/returnType}}
         {{^returnType}}
+        {{#objcCompatible}}
+        completion(error)
+        {{/objcCompatible}}
+        {{^objcCompatible}}
             if error == nil {
                 completion((), error)
             } else {
                 completion(nil, error)
             }
+        {{/objcCompatible}}
         {{/returnType}}
         }
     }
diff --git a/modules/openapi-generator/src/main/resources/swift4/modelObject.mustache b/modules/openapi-generator/src/main/resources/swift4/modelObject.mustache
index d477ac7880d6..8e7afc4977d0 100644
--- a/modules/openapi-generator/src/main/resources/swift4/modelObject.mustache
+++ b/modules/openapi-generator/src/main/resources/swift4/modelObject.mustache
@@ -1,5 +1,5 @@
-
-public struct {{classname}}: Codable {
+{{#objcCompatible}}@objc public class {{classname}}: NSObject, Codable { {{/objcCompatible}}
+{{^objcCompatible}}public struct {{classname}}: Codable { {{/objcCompatible}}
 
 {{#allVars}}
 {{#isEnum}}
@@ -9,14 +9,14 @@ public struct {{classname}}: Codable {
 {{#allVars}}
 {{#isEnum}}
     {{#description}}/** {{description}} */
-    {{/description}}public var {{name}}: {{{datatypeWithEnum}}}{{#unwrapRequired}}?{{/unwrapRequired}}{{^unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}{{#defaultValue}} = {{{defaultValue}}}{{/defaultValue}}
+    {{/description}}{{#objcCompatible}}@objc {{/objcCompatible}}public var {{name}}: {{{datatypeWithEnum}}}{{#unwrapRequired}}?{{/unwrapRequired}}{{^unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}{{#defaultValue}} = {{{defaultValue}}}{{/defaultValue}}
 {{/isEnum}}
 {{^isEnum}}
     {{#description}}/** {{description}} */
-    {{/description}}public var {{name}}: {{{datatype}}}{{#unwrapRequired}}?{{/unwrapRequired}}{{^unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}{{#defaultValue}} = {{{defaultValue}}}{{/defaultValue}}{{#objcCompatible}}{{#vendorExtensions.x-swift-optional-scalar}}
-    public var {{name}}Num: NSNumber? {
+    {{/description}}{{#objcCompatible}}{{#required}}@objc {{/required}}{{^required}}{{^vendorExtensions.x-swift-optional-scalar}}@objc {{/vendorExtensions.x-swift-optional-scalar}}{{/required}}{{/objcCompatible}}public var {{name}}: {{{datatype}}}{{#unwrapRequired}}?{{/unwrapRequired}}{{^unwrapRequired}}{{^required}}?{{/required}}{{/unwrapRequired}}{{#defaultValue}} = {{{defaultValue}}}{{/defaultValue}}{{#objcCompatible}}{{#vendorExtensions.x-swift-optional-scalar}}
+    @objc public var {{name}}Num: NSNumber? {
         get {
-            return {{name}}.map({ return NSNumber(value: $0) })
+            return {{name}} as NSNumber?
         }
     }{{/vendorExtensions.x-swift-optional-scalar}}{{/objcCompatible}}
 {{/isEnum}}