diff --git a/src/client/interfaces/Model.d.ts b/src/client/interfaces/Model.d.ts
index 057e52d8..13e722cb 100644
--- a/src/client/interfaces/Model.d.ts
+++ b/src/client/interfaces/Model.d.ts
@@ -9,7 +9,7 @@ export interface Model extends Schema {
     template: string | null;
     link: Model | null;
     description: string | null;
-    default?: any;
+    default?: string;
     imports: string[];
     extends: string[];
     enum: Enum[];
diff --git a/src/openApi/v2/parser/getOperationParameter.ts b/src/openApi/v2/parser/getOperationParameter.ts
index 665c5985..48c078da 100644
--- a/src/openApi/v2/parser/getOperationParameter.ts
+++ b/src/openApi/v2/parser/getOperationParameter.ts
@@ -53,7 +53,6 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
         operationParameter.template = definitionRef.template;
         operationParameter.imports.push(...definitionRef.imports);
         operationParameter.default = getOperationParameterDefault(parameter, operationParameter);
-        operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
         return operationParameter;
     }
 
@@ -66,7 +65,6 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
             operationParameter.base = PrimaryType.STRING;
             operationParameter.enum.push(...extendedEnumerators);
             operationParameter.default = getOperationParameterDefault(parameter, operationParameter);
-            operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
             return operationParameter;
         }
     }
@@ -79,7 +77,6 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
             operationParameter.base = PrimaryType.NUMBER;
             operationParameter.enum.push(...enumerators);
             operationParameter.default = getOperationParameterDefault(parameter, operationParameter);
-            operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
             return operationParameter;
         }
     }
@@ -92,7 +89,6 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
         operationParameter.template = items.template;
         operationParameter.imports.push(...items.imports);
         operationParameter.default = getOperationParameterDefault(parameter, operationParameter);
-        operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
         return operationParameter;
     }
 
@@ -105,7 +101,6 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
         operationParameter.imports.push(...items.imports);
         operationParameter.imports.push('Dictionary');
         operationParameter.default = getOperationParameterDefault(parameter, operationParameter);
-        operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
         return operationParameter;
     }
 
@@ -118,7 +113,6 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
             operationParameter.template = model.template;
             operationParameter.imports.push(...model.imports);
             operationParameter.default = getOperationParameterDefault(parameter, operationParameter);
-            operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
             return operationParameter;
         } else {
             const model = getModel(openApi, parameter.schema);
@@ -133,7 +127,6 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
             operationParameter.enums.push(...model.enums);
             operationParameter.properties.push(...model.properties);
             operationParameter.default = getOperationParameterDefault(parameter, operationParameter);
-            operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
             return operationParameter;
         }
     }
@@ -147,7 +140,6 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
         operationParameter.template = definitionType.template;
         operationParameter.imports.push(...definitionType.imports);
         operationParameter.default = getOperationParameterDefault(parameter, operationParameter);
-        operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
         return operationParameter;
     }
 
diff --git a/src/openApi/v2/parser/getOperationParameterDefault.ts b/src/openApi/v2/parser/getOperationParameterDefault.ts
index 5471c213..9fd51cba 100644
--- a/src/openApi/v2/parser/getOperationParameterDefault.ts
+++ b/src/openApi/v2/parser/getOperationParameterDefault.ts
@@ -1,7 +1,7 @@
 import { OperationParameter } from '../../../client/interfaces/OperationParameter';
 import { OpenApiParameter } from '../interfaces/OpenApiParameter';
 
-export function getOperationParameterDefault(parameter: OpenApiParameter, operationParameter: OperationParameter): string | null {
+export function getOperationParameterDefault(parameter: OpenApiParameter, operationParameter: OperationParameter): string | undefined {
     if (parameter.default === null) {
         return 'null';
     }
@@ -27,5 +27,5 @@ export function getOperationParameterDefault(parameter: OpenApiParameter, operat
             }
     }
 
-    return null;
+    return;
 }
diff --git a/src/openApi/v2/parser/sortByRequired.ts b/src/openApi/v2/parser/sortByRequired.ts
index bfcd0c7b..6ded692b 100644
--- a/src/openApi/v2/parser/sortByRequired.ts
+++ b/src/openApi/v2/parser/sortByRequired.ts
@@ -1,5 +1,27 @@
 import { OperationParameter } from '../../../client/interfaces/OperationParameter';
 
+/**
+ * Sort by required and default values creating the following order:
+ * 1. Parameters that are required and have no default value
+ * 2. Parameters that are optional and have no default value
+ * 3. Parameters that are required and have a default value
+ * 4. Parameters that are optional and have a default value
+ *
+ * Resulting in the following order:
+ *
+ * function myFunction(param1: string, param2?: string, param3: string = 'hello') {
+ *    ...
+ * }
+ *
+ * @param a
+ * @param b
+ */
 export function sortByRequired(a: OperationParameter, b: OperationParameter): number {
-    return a.isRequired && !b.isRequired ? -1 : !a.isRequired && b.isRequired ? 1 : 0;
+    const aHasDefaultValue = a.default !== undefined;
+    const bHasDefaultValue = b.default !== undefined;
+    if (aHasDefaultValue && !bHasDefaultValue) return 1;
+    if (!aHasDefaultValue && bHasDefaultValue) return -1;
+    if (a.isRequired && !b.isRequired) return -1;
+    if (!a.isRequired && b.isRequired) return 1;
+    return 0;
 }
diff --git a/src/openApi/v3/parser/getModelDefault.ts b/src/openApi/v3/parser/getModelDefault.ts
index cfb317ab..3064efc7 100644
--- a/src/openApi/v3/parser/getModelDefault.ts
+++ b/src/openApi/v3/parser/getModelDefault.ts
@@ -1,7 +1,7 @@
 import { Model } from '../../../client/interfaces/Model';
 import { OpenApiSchema } from '../interfaces/OpenApiSchema';
 
-export function getModelDefault(definition: OpenApiSchema, model?: Model): string | null {
+export function getModelDefault(definition: OpenApiSchema, model?: Model): string | undefined {
     if (definition.default === null) {
         return 'null';
     }
@@ -27,5 +27,5 @@ export function getModelDefault(definition: OpenApiSchema, model?: Model): strin
             }
     }
 
-    return null;
+    return;
 }
diff --git a/src/openApi/v3/parser/getOperationParameter.ts b/src/openApi/v3/parser/getOperationParameter.ts
index 73a12b73..721153bf 100644
--- a/src/openApi/v3/parser/getOperationParameter.ts
+++ b/src/openApi/v3/parser/getOperationParameter.ts
@@ -49,7 +49,7 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
             operationParameter.template = model.template;
             operationParameter.imports.push(...model.imports);
             operationParameter.default = getModelDefault(parameter.schema);
-            operationParameter.isRequired = operationParameter.isRequired || operationParameter.default;
+            operationParameter.isRequired = operationParameter.isRequired;
             return operationParameter;
         } else {
             const model = getModel(openApi, parameter.schema);
@@ -59,7 +59,7 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
             operationParameter.template = model.template;
             operationParameter.link = model.link;
             operationParameter.isReadOnly = model.isReadOnly;
-            operationParameter.isRequired = operationParameter.isRequired || model.isRequired || model.default;
+            operationParameter.isRequired = operationParameter.isRequired || model.isRequired;
             operationParameter.isNullable = operationParameter.isNullable || model.isNullable;
             operationParameter.format = model.format;
             operationParameter.maximum = model.maximum;
diff --git a/src/openApi/v3/parser/sortByRequired.ts b/src/openApi/v3/parser/sortByRequired.ts
index bfcd0c7b..6ded692b 100644
--- a/src/openApi/v3/parser/sortByRequired.ts
+++ b/src/openApi/v3/parser/sortByRequired.ts
@@ -1,5 +1,27 @@
 import { OperationParameter } from '../../../client/interfaces/OperationParameter';
 
+/**
+ * Sort by required and default values creating the following order:
+ * 1. Parameters that are required and have no default value
+ * 2. Parameters that are optional and have no default value
+ * 3. Parameters that are required and have a default value
+ * 4. Parameters that are optional and have a default value
+ *
+ * Resulting in the following order:
+ *
+ * function myFunction(param1: string, param2?: string, param3: string = 'hello') {
+ *    ...
+ * }
+ *
+ * @param a
+ * @param b
+ */
 export function sortByRequired(a: OperationParameter, b: OperationParameter): number {
-    return a.isRequired && !b.isRequired ? -1 : !a.isRequired && b.isRequired ? 1 : 0;
+    const aHasDefaultValue = a.default !== undefined;
+    const bHasDefaultValue = b.default !== undefined;
+    if (aHasDefaultValue && !bHasDefaultValue) return 1;
+    if (!aHasDefaultValue && bHasDefaultValue) return -1;
+    if (a.isRequired && !b.isRequired) return -1;
+    if (!a.isRequired && b.isRequired) return 1;
+    return 0;
 }
diff --git a/src/templates/partials/isRequired.hbs b/src/templates/partials/isRequired.hbs
index 50deb796..dbecae99 100644
--- a/src/templates/partials/isRequired.hbs
+++ b/src/templates/partials/isRequired.hbs
@@ -1 +1,5 @@
-{{#unless isRequired}}?{{/unless}}
+{{#if @root.useOptions}}
+{{~#unless isRequired}}?{{else if default}}?{{/unless~}}
+{{else}}
+{{~#unless isRequired}}{{#unless default}}?{{/unless}}{{/unless~}}
+{{/if}}
diff --git a/test/__snapshots__/index.spec.js.snap b/test/__snapshots__/index.spec.js.snap
index c9516210..c28bedfc 100644
--- a/test/__snapshots__/index.spec.js.snap
+++ b/test/__snapshots__/index.spec.js.snap
@@ -1999,11 +1999,11 @@ import { OpenAPI } from '../core/OpenAPI';
 export class DefaultsService {
 
     /**
-     * @param parameterString This is a simple string
-     * @param parameterNumber This is a simple number
-     * @param parameterBoolean This is a simple boolean
-     * @param parameterEnum This is a simple enum
-     * @param parameterModel This is a simple model
+     * @param parameterString This is a simple string with default value
+     * @param parameterNumber This is a simple number with default value
+     * @param parameterBoolean This is a simple boolean with default value
+     * @param parameterEnum This is a simple enum with default value
+     * @param parameterModel This is a simple model with default value
      * @throws ApiError
      */
     public static async callWithDefaultParameters({
@@ -2015,11 +2015,11 @@ export class DefaultsService {
             \\"prop\\": \\"Hello World\\"
         },
     }: {
-        parameterString: string,
-        parameterNumber: number,
-        parameterBoolean: boolean,
-        parameterEnum: ('Success' | 'Warning' | 'Error'),
-        parameterModel: ModelThatExtends | ModelThatExtendsExtends | ModelWithString,
+        parameterString?: string,
+        parameterNumber?: number,
+        parameterBoolean?: boolean,
+        parameterEnum?: ('Success' | 'Warning' | 'Error'),
+        parameterModel?: ModelThatExtends | ModelThatExtendsExtends | ModelWithString,
     }): Promise<void> {
 
         const result = await __request({
@@ -2039,6 +2039,90 @@ export class DefaultsService {
         return result.body;
     }
 
+    /**
+     * @param parameterString This is a simple string that is optional with default value
+     * @param parameterNumber This is a simple number that is optional with default value
+     * @param parameterBoolean This is a simple boolean that is optional with default value
+     * @param parameterEnum This is a simple enum that is optional with default value
+     * @param parameterModel This is a simple model that is optional with default value
+     * @throws ApiError
+     */
+    public static async callWithDefaultOptionalParameters({
+        parameterString = 'Hello World!',
+        parameterNumber = 123,
+        parameterBoolean = true,
+        parameterEnum = 'Success',
+        parameterModel = {
+            \\"prop\\": \\"Hello World\\"
+        },
+    }: {
+        parameterString?: string,
+        parameterNumber?: number,
+        parameterBoolean?: boolean,
+        parameterEnum?: ('Success' | 'Warning' | 'Error'),
+        parameterModel?: ModelThatExtends | ModelThatExtendsExtends | ModelWithString,
+    }): Promise<void> {
+
+        const result = await __request({
+            method: 'post',
+            path: \`/api/v\${OpenAPI.VERSION}/defaults\`,
+            query: {
+                'parameterString': parameterString,
+                'parameterNumber': parameterNumber,
+                'parameterBoolean': parameterBoolean,
+                'parameterEnum': parameterEnum,
+                'parameterModel': parameterModel,
+            },
+        });
+
+        catchGenericError(result);
+
+        return result.body;
+    }
+
+    /**
+     * @param parameterStringWithNoDefault This is a string with no default
+     * @param parameterOptionalStringWithNoDefault This is a optional string with no default
+     * @param parameterStringWithDefault This is a string with default
+     * @param parameterStringWithEmptyDefault This is a string with empty default
+     * @param parameterOptionalStringWithDefault This is a optional string with default
+     * @param parameterOptionalStringWithEmptyDefault This is a optional string with empty default
+     * @throws ApiError
+     */
+    public static async callToTestOrderOfParams({
+        parameterStringWithNoDefault,
+        parameterOptionalStringWithNoDefault,
+        parameterStringWithDefault = 'hello',
+        parameterStringWithEmptyDefault = '',
+        parameterOptionalStringWithDefault = 'Hello World!',
+        parameterOptionalStringWithEmptyDefault = '',
+    }: {
+        parameterStringWithNoDefault: string,
+        parameterOptionalStringWithNoDefault?: string,
+        parameterStringWithDefault?: string,
+        parameterStringWithEmptyDefault?: string,
+        parameterOptionalStringWithDefault?: string,
+        parameterOptionalStringWithEmptyDefault?: string,
+    }): Promise<void> {
+
+        const result = await __request({
+            method: 'put',
+            path: \`/api/v\${OpenAPI.VERSION}/defaults\`,
+            query: {
+                'parameterStringWithNoDefault': parameterStringWithNoDefault,
+                'parameterOptionalStringWithNoDefault': parameterOptionalStringWithNoDefault,
+                'parameterStringWithDefault': parameterStringWithDefault,
+                'parameterStringWithEmptyDefault': parameterStringWithEmptyDefault,
+                'parameterOptionalStringWithDefault': parameterOptionalStringWithDefault,
+                'parameterOptionalStringWithEmptyDefault': parameterOptionalStringWithEmptyDefault,
+            },
+        });
+
+        catchGenericError(result);
+
+        return result.body;
+    }
+
 }"
 `;
 
@@ -2476,14 +2560,14 @@ import { OpenAPI } from '../core/OpenAPI';
 export class TypesService {
 
     /**
-     * @param parameterNumber This is a number parameter
-     * @param parameterString This is a string parameter
-     * @param parameterBoolean This is a boolean parameter
-     * @param parameterObject This is an object parameter
      * @param parameterArray This is an array parameter
      * @param parameterDictionary This is a dictionary parameter
      * @param parameterEnum This is an enum parameter
      * @param id This is a number parameter
+     * @param parameterNumber This is a number parameter
+     * @param parameterString This is a string parameter
+     * @param parameterBoolean This is a boolean parameter
+     * @param parameterObject This is an object parameter
      * @result number Response is a simple number
      * @result string Response is a simple string
      * @result boolean Response is a simple boolean
@@ -2491,36 +2575,36 @@ export class TypesService {
      * @throws ApiError
      */
     public static async types({
-        parameterNumber = 123,
-        parameterString = 'default',
-        parameterBoolean = true,
-        parameterObject = null,
         parameterArray,
         parameterDictionary,
         parameterEnum,
         id,
+        parameterNumber = 123,
+        parameterString = 'default',
+        parameterBoolean = true,
+        parameterObject = null,
     }: {
-        parameterNumber: number,
-        parameterString: string,
-        parameterBoolean: boolean,
-        parameterObject: any,
         parameterArray: Array<string>,
         parameterDictionary: Dictionary<string>,
         parameterEnum: ('Success' | 'Warning' | 'Error'),
         id?: number,
+        parameterNumber?: number,
+        parameterString?: string,
+        parameterBoolean?: boolean,
+        parameterObject?: any,
     }): Promise<number | string | boolean | any> {
 
         const result = await __request({
             method: 'get',
             path: \`/api/v\${OpenAPI.VERSION}/types\`,
             query: {
+                'parameterArray': parameterArray,
+                'parameterDictionary': parameterDictionary,
+                'parameterEnum': parameterEnum,
                 'parameterNumber': parameterNumber,
                 'parameterString': parameterString,
                 'parameterBoolean': parameterBoolean,
                 'parameterObject': parameterObject,
-                'parameterArray': parameterArray,
-                'parameterDictionary': parameterDictionary,
-                'parameterEnum': parameterEnum,
             },
         });
 
@@ -4660,11 +4744,11 @@ import { OpenAPI } from '../core/OpenAPI';
 export class DefaultsService {
 
     /**
-     * @param parameterString This is a simple string
-     * @param parameterNumber This is a simple number
-     * @param parameterBoolean This is a simple boolean
-     * @param parameterEnum This is a simple enum
-     * @param parameterModel This is a simple model
+     * @param parameterString This is a simple string with default value
+     * @param parameterNumber This is a simple number with default value
+     * @param parameterBoolean This is a simple boolean with default value
+     * @param parameterEnum This is a simple enum with default value
+     * @param parameterModel This is a simple model with default value
      * @throws ApiError
      */
     public static async callWithDefaultParameters({
@@ -4676,11 +4760,11 @@ export class DefaultsService {
             \\"prop\\": \\"Hello World\\"
         },
     }: {
-        parameterString: string | null,
-        parameterNumber: number | null,
-        parameterBoolean: boolean | null,
-        parameterEnum: ('Success' | 'Warning' | 'Error'),
-        parameterModel: ModelThatExtends | ModelThatExtendsExtends | ModelWithString | null,
+        parameterString?: string | null,
+        parameterNumber?: number | null,
+        parameterBoolean?: boolean | null,
+        parameterEnum?: ('Success' | 'Warning' | 'Error'),
+        parameterModel?: ModelThatExtends | ModelThatExtendsExtends | ModelWithString | null,
     }): Promise<void> {
 
         const result = await __request({
@@ -4700,6 +4784,90 @@ export class DefaultsService {
         return result.body;
     }
 
+    /**
+     * @param parameterString This is a simple string that is optional with default value
+     * @param parameterNumber This is a simple number that is optional with default value
+     * @param parameterBoolean This is a simple boolean that is optional with default value
+     * @param parameterEnum This is a simple enum that is optional with default value
+     * @param parameterModel This is a simple model that is optional with default value
+     * @throws ApiError
+     */
+    public static async callWithDefaultOptionalParameters({
+        parameterString = 'Hello World!',
+        parameterNumber = 123,
+        parameterBoolean = true,
+        parameterEnum = 'Success',
+        parameterModel = {
+            \\"prop\\": \\"Hello World\\"
+        },
+    }: {
+        parameterString?: string,
+        parameterNumber?: number,
+        parameterBoolean?: boolean,
+        parameterEnum?: ('Success' | 'Warning' | 'Error'),
+        parameterModel?: ModelThatExtends | ModelThatExtendsExtends | ModelWithString,
+    }): Promise<void> {
+
+        const result = await __request({
+            method: 'post',
+            path: \`/api/v\${OpenAPI.VERSION}/defaults\`,
+            query: {
+                'parameterString': parameterString,
+                'parameterNumber': parameterNumber,
+                'parameterBoolean': parameterBoolean,
+                'parameterEnum': parameterEnum,
+                'parameterModel': parameterModel,
+            },
+        });
+
+        catchGenericError(result);
+
+        return result.body;
+    }
+
+    /**
+     * @param parameterStringWithNoDefault This is a string with no default
+     * @param parameterOptionalStringWithNoDefault This is a optional string with no default
+     * @param parameterStringWithDefault This is a string with default
+     * @param parameterStringWithEmptyDefault This is a string with empty default
+     * @param parameterOptionalStringWithDefault This is a optional string with default
+     * @param parameterOptionalStringWithEmptyDefault This is a optional string with empty default
+     * @throws ApiError
+     */
+    public static async callToTestOrderOfParams({
+        parameterStringWithNoDefault,
+        parameterOptionalStringWithNoDefault,
+        parameterStringWithDefault = 'hello',
+        parameterStringWithEmptyDefault = '',
+        parameterOptionalStringWithDefault = 'hello',
+        parameterOptionalStringWithEmptyDefault = '',
+    }: {
+        parameterStringWithNoDefault: string,
+        parameterOptionalStringWithNoDefault?: string,
+        parameterStringWithDefault?: string,
+        parameterStringWithEmptyDefault?: string,
+        parameterOptionalStringWithDefault?: string,
+        parameterOptionalStringWithEmptyDefault?: string,
+    }): Promise<void> {
+
+        const result = await __request({
+            method: 'put',
+            path: \`/api/v\${OpenAPI.VERSION}/defaults\`,
+            query: {
+                'parameterStringWithNoDefault': parameterStringWithNoDefault,
+                'parameterOptionalStringWithNoDefault': parameterOptionalStringWithNoDefault,
+                'parameterStringWithDefault': parameterStringWithDefault,
+                'parameterStringWithEmptyDefault': parameterStringWithEmptyDefault,
+                'parameterOptionalStringWithDefault': parameterOptionalStringWithDefault,
+                'parameterOptionalStringWithEmptyDefault': parameterOptionalStringWithEmptyDefault,
+            },
+        });
+
+        catchGenericError(result);
+
+        return result.body;
+    }
+
 }"
 `;
 
@@ -5242,14 +5410,14 @@ import { OpenAPI } from '../core/OpenAPI';
 export class TypesService {
 
     /**
-     * @param parameterNumber This is a number parameter
-     * @param parameterString This is a string parameter
-     * @param parameterBoolean This is a boolean parameter
-     * @param parameterObject This is an object parameter
      * @param parameterArray This is an array parameter
      * @param parameterDictionary This is a dictionary parameter
      * @param parameterEnum This is an enum parameter
      * @param id This is a number parameter
+     * @param parameterNumber This is a number parameter
+     * @param parameterString This is a string parameter
+     * @param parameterBoolean This is a boolean parameter
+     * @param parameterObject This is an object parameter
      * @result number Response is a simple number
      * @result string Response is a simple string
      * @result boolean Response is a simple boolean
@@ -5257,36 +5425,36 @@ export class TypesService {
      * @throws ApiError
      */
     public static async types({
-        parameterNumber = 123,
-        parameterString = 'default',
-        parameterBoolean = true,
-        parameterObject = null,
         parameterArray,
         parameterDictionary,
         parameterEnum,
         id,
+        parameterNumber = 123,
+        parameterString = 'default',
+        parameterBoolean = true,
+        parameterObject = null,
     }: {
-        parameterNumber: number,
-        parameterString: string | null,
-        parameterBoolean: boolean | null,
-        parameterObject: any,
         parameterArray: Array<string> | null,
         parameterDictionary: any,
         parameterEnum: ('Success' | 'Warning' | 'Error') | null,
         id?: number,
+        parameterNumber?: number,
+        parameterString?: string | null,
+        parameterBoolean?: boolean | null,
+        parameterObject?: any,
     }): Promise<number | string | boolean | any> {
 
         const result = await __request({
             method: 'get',
             path: \`/api/v\${OpenAPI.VERSION}/types\`,
             query: {
+                'parameterArray': parameterArray,
+                'parameterDictionary': parameterDictionary,
+                'parameterEnum': parameterEnum,
                 'parameterNumber': parameterNumber,
                 'parameterString': parameterString,
                 'parameterBoolean': parameterBoolean,
                 'parameterObject': parameterObject,
-                'parameterArray': parameterArray,
-                'parameterDictionary': parameterDictionary,
-                'parameterEnum': parameterEnum,
             },
         });
 
diff --git a/test/mock/v2/spec.json b/test/mock/v2/spec.json
index 6673810b..fac43da5 100644
--- a/test/mock/v2/spec.json
+++ b/test/mock/v2/spec.json
@@ -171,28 +171,86 @@
                 "operationId": "CallWithDefaultParameters",
                 "parameters": [
                     {
-                        "description": "This is a simple string",
+                        "description": "This is a simple string with default value",
+                        "name": "parameterString",
+                        "in": "query",
+                        "required": true,
+                        "default": "Hello World!",
+                        "type": "string"
+                    },
+                    {
+                        "description": "This is a simple number with default value",
+                        "name": "parameterNumber",
+                        "in": "query",
+                        "required": true,
+                        "default": 123,
+                        "type": "number"
+                    },
+                    {
+                        "description": "This is a simple boolean with default value",
+                        "name": "parameterBoolean",
+                        "in": "query",
+                        "required": true,
+                        "default": true,
+                        "type": "boolean"
+                    },
+                    {
+                        "description": "This is a simple enum with default value",
+                        "name": "parameterEnum",
+                        "in": "query",
+                        "required": true,
+                        "default": 0,
+                        "schema": {
+                            "enum": [
+                                "Success",
+                                "Warning",
+                                "Error"
+                            ]
+                        }
+                    },
+                    {
+                        "description": "This is a simple model with default value",
+                        "name": "parameterModel",
+                        "in": "query",
+                        "required": true,
+                        "default": {
+                            "prop": "Hello World"
+                        },
+                        "schema": {
+                            "$ref": "#/definitions/ModelWithString"
+                        }
+                    }
+                ]
+            },
+            "post": {
+                "tags": [
+                    "Defaults"
+                ],
+                "operationId": "CallWithDefaultOptionalParameters",
+                "parameters": [
+                    {
+                        "description": "This is a simple string that is optional with default value",
                         "name": "parameterString",
                         "in": "query",
                         "default": "Hello World!",
                         "type": "string"
                     },
                     {
-                        "description": "This is a simple number",
+                        "description": "This is a simple number that is optional with default value",
                         "name": "parameterNumber",
                         "in": "query",
                         "default": 123,
                         "type": "number"
                     },
                     {
-                        "description": "This is a simple boolean",
+                        "description": "This is a simple boolean that is optional with default value",
                         "name": "parameterBoolean",
                         "in": "query",
                         "default": true,
                         "type": "boolean"
                     },
                     {
-                        "description": "This is a simple enum",
+                        "description": "This is a simple enum that is optional with default value",
                         "name": "parameterEnum",
                         "in": "query",
                         "default": 0,
@@ -205,7 +263,7 @@
                         }
                     },
                     {
-                        "description": "This is a simple model",
+                        "description": "This is a simple model that is optional with default value",
                         "name": "parameterModel",
                         "in": "query",
                         "default": {
@@ -216,6 +274,60 @@
                         }
                     }
                 ]
+            },
+            "put": {
+                "tags": [
+                    "Defaults"
+                ],
+                "operationId": "CallToTestOrderOfParams",
+                "parameters": [
+                    {
+                        "description": "This is a optional string with default",
+                        "name": "parameterOptionalStringWithDefault",
+                        "in": "query",
+                        "required": false,
+                        "default": "Hello World!",
+                        "type": "string"
+                    },
+                    {
+                        "description": "This is a optional string with empty default",
+                        "name": "parameterOptionalStringWithEmptyDefault",
+                        "in": "query",
+                        "required": false,
+                        "default": "",
+                        "type": "string"
+                    },
+                    {
+                        "description": "This is a optional string with no default",
+                        "name": "parameterOptionalStringWithNoDefault",
+                        "in": "query",
+                        "required": false,
+                        "type": "string"
+                    },
+                    {
+                        "description": "This is a string with default",
+                        "name": "parameterStringWithDefault",
+                        "in": "query",
+                        "required": true,
+                        "default": "hello",
+                        "type": "string"
+                    },
+                    {
+                        "description": "This is a string with empty default",
+                        "name": "parameterStringWithEmptyDefault",
+                        "in": "query",
+                        "required": true,
+                        "default": "",
+                        "type": "string"
+                    },
+                    {
+                        "description": "This is a string with no default",
+                        "name": "parameterStringWithNoDefault",
+                        "in": "query",
+                        "required": true,
+                        "type": "string"
+                    }
+                ]
             }
         },
         "/api/v{api-version}/duplicate": {
diff --git a/test/mock/v3/spec.json b/test/mock/v3/spec.json
index 3105e5cb..94ef2c18 100644
--- a/test/mock/v3/spec.json
+++ b/test/mock/v3/spec.json
@@ -296,7 +296,7 @@
                 "operationId": "CallWithDefaultParameters",
                 "parameters": [
                     {
-                        "description": "This is a simple string",
+                        "description": "This is a simple string with default value",
                         "name": "parameterString",
                         "in": "query",
                         "nullable": true,
@@ -306,7 +306,7 @@
                         }
                     },
                     {
-                        "description": "This is a simple number",
+                        "description": "This is a simple number with default value",
                         "name": "parameterNumber",
                         "in": "query",
                         "nullable": true,
@@ -316,7 +316,7 @@
                         }
                     },
                     {
-                        "description": "This is a simple boolean",
+                        "description": "This is a simple boolean with default value",
                         "name": "parameterBoolean",
                         "in": "query",
                         "nullable": true,
@@ -326,7 +326,7 @@
                         }
                     },
                     {
-                        "description": "This is a simple enum",
+                        "description": "This is a simple enum with default value",
                         "name": "parameterEnum",
                         "in": "query",
                         "schema": {
@@ -339,7 +339,7 @@
                         }
                     },
                     {
-                        "description": "This is a simple model",
+                        "description": "This is a simple model with default value",
                         "name": "parameterModel",
                         "in": "query",
                         "nullable": true,
@@ -351,6 +351,136 @@
                         }
                     }
                 ]
+            },
+            "post": {
+                "tags": [
+                    "Defaults"
+                ],
+                "operationId": "CallWithDefaultOptionalParameters",
+                "parameters": [
+                    {
+                        "description": "This is a simple string that is optional with default value",
+                        "name": "parameterString",
+                        "in": "query",
+                        "required": false,
+                        "schema": {
+                            "type": "string",
+                            "default": "Hello World!"
+                        }
+                    },
+                    {
+                        "description": "This is a simple number that is optional with default value",
+                        "name": "parameterNumber",
+                        "in": "query",
+                        "required": false,
+                        "schema": {
+                            "type": "number",
+                            "default": 123
+                        }
+                    },
+                    {
+                        "description": "This is a simple boolean that is optional with default value",
+                        "name": "parameterBoolean",
+                        "in": "query",
+                        "required": false,
+                        "schema": {
+                            "type": "boolean",
+                            "default": true
+                        }
+                    },
+                    {
+                        "description": "This is a simple enum that is optional with default value",
+                        "name": "parameterEnum",
+                        "in": "query",
+                        "required": false,
+                        "schema": {
+                            "enum": [
+                                "Success",
+                                "Warning",
+                                "Error"
+                            ],
+                            "default": 0
+                        }
+                    },
+                    {
+                        "description": "This is a simple model that is optional with default value",
+                        "name": "parameterModel",
+                        "in": "query",
+                        "required": false,
+                        "schema": {
+                            "$ref": "#/components/schemas/ModelWithString",
+                            "default": {
+                                "prop": "Hello World"
+                            }
+                        }
+                    }
+                ]
+            },
+            "put": {
+                "tags": [
+                    "Defaults"
+                ],
+                "operationId": "CallToTestOrderOfParams",
+                "parameters": [
+                    {
+                        "description": "This is a optional string with default",
+                        "name": "parameterOptionalStringWithDefault",
+                        "in": "query",
+                        "required": false,
+                        "schema": {
+                            "type": "string",
+                            "default": "hello"
+                        }
+                    },
+                    {
+                        "description": "This is a optional string with empty default",
+                        "name": "parameterOptionalStringWithEmptyDefault",
+                        "in": "query",
+                        "required": false,
+                        "schema": {
+                            "type": "string",
+                            "default": ""
+                        }
+                    },
+                    {
+                        "description": "This is a optional string with no default",
+                        "name": "parameterOptionalStringWithNoDefault",
+                        "in": "query",
+                        "required": false,
+                        "schema": {
+                            "type": "string"
+                        }
+                    },
+                    {
+                        "description": "This is a string with default",
+                        "name": "parameterStringWithDefault",
+                        "in": "query",
+                        "required": true,
+                        "schema": {
+                            "type": "string",
+                            "default": "hello"
+                        }
+                    },
+                    {
+                        "description": "This is a string with empty default",
+                        "name": "parameterStringWithEmptyDefault",
+                        "in": "query",
+                        "required": true,
+                        "schema": {
+                            "type": "string",
+                            "default": ""
+                        }
+                    },
+                    {
+                        "description": "This is a string with no default",
+                        "name": "parameterStringWithNoDefault",
+                        "in": "query",
+                        "required": true,
+                        "schema": {
+                            "type": "string"
+                        }
+                    }
+                ]
             }
         },
         "/api/v{api-version}/duplicate": {