diff --git a/opapi/package.json b/opapi/package.json
index 03d63e231..ed0cab95a 100644
--- a/opapi/package.json
+++ b/opapi/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@bpinternal/opapi",
-  "version": "0.18.0",
+  "version": "0.18.1",
   "description": "Opapi is a highly opinionated library to generate server, client and documentation from OpenAPI specification using typescript.",
   "main": "./dist/index.js",
   "module": "./dist/index.mjs",
diff --git a/opapi/src/opapi.ts b/opapi/src/opapi.ts
index 5041d47c9..58d4b4c2b 100644
--- a/opapi/src/opapi.ts
+++ b/opapi/src/opapi.ts
@@ -98,7 +98,7 @@ function exportClient(state: State<string, string, string>) {
       options = propsOrEndpoint
     }
 
-    state = applyExportOptions(state, postProcessorsAndStateOpts)
+    state = applyExportOptions(state, options)
 
     if (options.generator === 'openapi-generator') {
       return generateClientWithOpenapiGenerator(state, dir, options.endpoint, options.postProcessors)
diff --git a/opapi/test/api.ts b/opapi/test/api.ts
index 9c39f55de..b0598ed2e 100644
--- a/opapi/test/api.ts
+++ b/opapi/test/api.ts
@@ -44,6 +44,14 @@ export const getMockApi = () => {
         type: 'FooNotFound',
       },
     ],
+    defaultParameters: {
+      xFoo: {
+        in: 'header',
+        description: 'Foo',
+        type: 'string',
+        required: true,
+      },
+    },
     metadata: {
       title: 'Test API',
       description: 'Test API',
diff --git a/opapi/test/client.test.ts b/opapi/test/client.test.ts
index 809c924c7..2497687e7 100644
--- a/opapi/test/client.test.ts
+++ b/opapi/test/client.test.ts
@@ -1,8 +1,9 @@
-import { describe, it } from 'vitest'
+import { describe, expect, it } from 'vitest'
 import { getMockApi } from './api'
 import { join } from 'path'
 import { getFiles } from '../src/file'
 import { validateTypescriptFile } from './util'
+import fs from 'node:fs'
 
 describe('client generator', () => {
   it('should be able to generate a client with openapi-generator', async () => {
@@ -38,4 +39,33 @@ describe('client generator', () => {
       }
     })
   })
+
+  it('should not include defaultParameters when ignoreDefaultParameters: true', async () => {
+    const genClientFolder = join(__dirname, 'gen/client-opapi-no-default')
+
+    const api = getMockApi()
+
+    await api.exportClient(genClientFolder, {
+      generator: 'opapi',
+      ignoreDefaultParameters: true,
+    })
+
+    const files = getFiles(genClientFolder)
+
+    files.forEach((file) => {
+      if (file.endsWith('.ts')) {
+        validateTypescriptFile(file)
+      }
+    })
+    await Promise.all(
+      files
+        .filter((file) => file.includes('operations'))
+        .map(async (file) => {
+          const content = fs.readFileSync(file, { encoding: 'utf8' })
+          if (content.includes('xFoo')) {
+            throw new Error(`'xFoo' parameter should not be included in ${file}`)
+          }
+        }),
+    )
+  })
 })