diff --git a/rollup.config.js b/rollup.config.js
index d563874c3..955807bcf 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -37,6 +37,7 @@ const handlebarsPlugin = () => ({
                     escapeComment: true,
                     escapeDescription: true,
                     camelCase: true,
+                    onceInList: true,
                 },
             });
             return `export default ${templateSpec};`;
diff --git a/src/templates/partials/parameters.hbs b/src/templates/partials/parameters.hbs
index 57ab5a7d1..22877cfa7 100644
--- a/src/templates/partials/parameters.hbs
+++ b/src/templates/partials/parameters.hbs
@@ -2,21 +2,25 @@
 {{#if @root.useOptions~}}
 {
 {{#each parameters}}
-{{{name}}}{{#if default}} = {{{default}}}{{/if}},
+	{{#onceInList ../parameters name}}
+		{{{name}}}{{#if default}} = {{{default}}}{{/if}},
+	{{/onceInList}}
 {{/each}}
 }: {
 {{#each parameters}}
-{{#ifdef description deprecated}}
-/**
-{{#if description}}
- * {{{escapeComment description}}}
-{{/if}}
-{{#if deprecated}}
- * @deprecated
-{{/if}}
- */
-{{/ifdef}}
-{{{name}}}{{>isRequired}}: {{>type}},
+	{{#onceInList ../parameters name}}
+		{{#ifdef description deprecated}}
+		/**
+		{{#if description}}
+		 * {{{escapeComment description}}}
+		{{/if}}
+		{{#if deprecated}}
+		 * @deprecated
+		{{/if}}
+		 */
+		{{/ifdef}}
+		{{{name}}}{{>isRequired}}: {{>type}},
+	{{/onceInList}}
 {{/each}}
 }
 {{~else}}
diff --git a/src/utils/registerHandlebarHelpers.ts b/src/utils/registerHandlebarHelpers.ts
index 88f47c19b..e362161e8 100644
--- a/src/utils/registerHandlebarHelpers.ts
+++ b/src/utils/registerHandlebarHelpers.ts
@@ -4,6 +4,7 @@ import { EOL } from 'os';
 
 import type { Enum } from '../client/interfaces/Enum';
 import type { Model } from '../client/interfaces/Model';
+import { OperationParameter } from '../client/interfaces/OperationParameter';
 import type { HttpClient } from '../HttpClient';
 import { unique } from './unique';
 
@@ -104,4 +105,17 @@ export const registerHandlebarHelpers = (root: {
     Handlebars.registerHelper('camelCase', function (value: string): string {
         return camelCase(value);
     });
+
+    Handlebars.registerHelper(
+        'onceInList',
+        function (this: any, list: OperationParameter[], name: string, options: Handlebars.HelperOptions): string {
+            const firstIndex = list.findIndex(param => param.name === name);
+
+            if (firstIndex === options.data.index || !list.slice(firstIndex + 1).some(param => param.name === name)) {
+                return options.fn(this);
+            } else {
+                return options.inverse(this);
+            }
+        }
+    );
 };