From 0317daf92184cade5146a7ef85009f8b62ca8d3e Mon Sep 17 00:00:00 2001
From: Lubos <lmenus@lmen.us>
Date: Sat, 20 Dec 2025 04:43:49 +0800
Subject: [PATCH] Revert "Fix: In axios client, proving NO paramsSerializer
 should use the `query` option for params"

---
 .../src/client/client/client.gen.ts           |  2 +-
 .../axios/client/client.gen.ts                |  2 +-
 .../react-query/axios/client/client.gen.ts    |  2 +-
 .../solid-query/axios/client/client.gen.ts    |  2 +-
 .../svelte-query/axios/client/client.gen.ts   |  2 +-
 .../vue-query/axios/client/client.gen.ts      |  2 +-
 .../3.0.x/content-types/client/client.gen.ts  |  2 +-
 .../client/client.gen.ts                      |  2 +-
 .../axios/client/client.gen.ts                |  2 +-
 .../react-query/axios/client/client.gen.ts    |  2 +-
 .../solid-query/axios/client/client.gen.ts    |  2 +-
 .../svelte-query/axios/client/client.gen.ts   |  2 +-
 .../vue-query/axios/client/client.gen.ts      |  2 +-
 .../base-url-false/client/client.gen.ts       |  2 +-
 .../base-url-number/client/client.gen.ts      |  2 +-
 .../base-url-strict/client/client.gen.ts      |  2 +-
 .../base-url-string/client/client.gen.ts      |  2 +-
 .../clean-false/client/client.gen.ts          |  2 +-
 .../client-axios/default/client/client.gen.ts |  2 +-
 .../client/client.gen.ts                      |  2 +-
 .../sdk-client-optional/client/client.gen.ts  |  2 +-
 .../sdk-client-required/client/client.gen.ts  |  2 +-
 .../client/client.gen.ts                      |  2 +-
 .../3.1.x/content-types/client/client.gen.ts  |  2 +-
 .../client/client.gen.ts                      |  2 +-
 .../axios/client/client.gen.ts                |  2 +-
 .../react-query/axios/client/client.gen.ts    |  2 +-
 .../solid-query/axios/client/client.gen.ts    |  2 +-
 .../svelte-query/axios/client/client.gen.ts   |  2 +-
 .../vue-query/axios/client/client.gen.ts      |  2 +-
 .../3.1.x/sse-axios/client/client.gen.ts      |  2 +-
 .../client-axios/__tests__/client.test.ts     | 52 -------------------
 .../@hey-api/client-axios/bundle/client.ts    |  2 +-
 33 files changed, 32 insertions(+), 84 deletions(-)

diff --git a/examples/openapi-ts-axios/src/client/client/client.gen.ts b/examples/openapi-ts-axios/src/client/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/examples/openapi-ts-axios/src/client/client/client.gen.ts
+++ b/examples/openapi-ts-axios/src/client/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/2.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/content-types/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/content-types/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/content-types/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/content-types/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/parameter-explode-false-axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/parameter-explode-false-axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/parameter-explode-false-axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/parameter-explode-false-axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.0.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-false/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-false/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-false/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-false/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-number/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-number/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-number/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-number/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-strict/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-strict/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-strict/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-strict/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-string/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-string/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-string/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/base-url-string/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/clean-false/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/clean-false/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/clean-false/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/clean-false/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/default/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/default/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/default/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/default/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/import-file-extension-ts/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/import-file-extension-ts/client/client.gen.ts
index 45d31a562..8bd1d5631 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/import-file-extension-ts/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/import-file-extension-ts/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-optional/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-optional/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-optional/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-optional/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-required/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-required/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-required/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/sdk-client-required/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/tsconfig-nodenext-sdk/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/tsconfig-nodenext-sdk/client/client.gen.ts
index 4a9cfc36e..f0000c3c1 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/tsconfig-nodenext-sdk/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/clients/@hey-api/client-axios/tsconfig-nodenext-sdk/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/content-types/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/content-types/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/content-types/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/content-types/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/parameter-explode-false-axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/parameter-explode-false-axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/parameter-explode-false-axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/parameter-explode-false-axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/angular-query-experimental/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/react-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/react-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/solid-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/svelte-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/plugins/@tanstack/vue-query/axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-axios/client/client.gen.ts b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-axios/client/client.gen.ts
index f7b9168dc..f81a9e786 100644
--- a/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-axios/client/client.gen.ts
+++ b/packages/openapi-ts-tests/main/test/__snapshots__/3.1.x/sse-axios/client/client.gen.ts
@@ -84,7 +84,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-axios/__tests__/client.test.ts b/packages/openapi-ts/src/plugins/@hey-api/client-axios/__tests__/client.test.ts
index 9894d4c48..f8fe1fa9a 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-axios/__tests__/client.test.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-axios/__tests__/client.test.ts
@@ -49,49 +49,6 @@ describe('buildUrl', () => {
   it.each(scenarios)('returns $url', ({ options, url }) => {
     expect(client.buildUrl(options)).toBe(url);
   });
-
-  it.each(scenarios)(
-    'correctly maps `query` parameter to `params` parameter for axios',
-    async ({ options }) => {
-      const mockAxios = vi.fn((config) => ({ config }));
-
-      expect(
-        (
-          await client.request({
-            ...options,
-            axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
-            method: 'GET',
-          })
-        ).config?.params,
-      ).toBe(options.query);
-    },
-  );
-
-  it.each(scenarios)(
-    'uses a custom `paramsSerializer` method when given and do not map `params` for axios',
-    async ({ options }) => {
-      const mockAxios = vi.fn((config) => ({ config }));
-
-      const paramsSerializer = (params: Record<string, string>) =>
-        new URLSearchParams(params).toString();
-
-      expect(
-        (
-          await client.request({
-            ...options,
-            axios: mockAxios as Partial<AxiosInstance> as AxiosInstance,
-            method: 'GET',
-            paramsSerializer,
-          })
-        ).config,
-      ).toEqual(
-        expect.objectContaining({
-          params: undefined,
-          paramsSerializer,
-        }),
-      );
-    },
-  );
 });
 
 describe('AxiosInstance', () => {
@@ -394,13 +351,4 @@ describe('confirming axios behaviour for constructing URLs', () => {
     const config = client.getUri({ baseURL: undefined, url: '/users' });
     expect(config).toBe('https://api.example.com/users');
   });
-  it('does append `params` as searchParams to the URL', async () => {
-    const client = axios.create({
-      baseURL: 'https://api.example.com',
-      params: { foo: 'bar' },
-    });
-
-    const config = client.getUri({ baseURL: undefined, url: '/users' });
-    expect(config).toBe('https://api.example.com/users?foo=bar');
-  });
 });
diff --git a/packages/openapi-ts/src/plugins/@hey-api/client-axios/bundle/client.ts b/packages/openapi-ts/src/plugins/@hey-api/client-axios/bundle/client.ts
index a2d0d2750..fcbbfea0b 100644
--- a/packages/openapi-ts/src/plugins/@hey-api/client-axios/bundle/client.ts
+++ b/packages/openapi-ts/src/plugins/@hey-api/client-axios/bundle/client.ts
@@ -82,7 +82,7 @@ export const createClient = (config: Config = {}): Client => {
         data: getValidRequestBody(opts),
         headers: opts.headers as RawAxiosRequestHeaders,
         // let `paramsSerializer()` handle query params if it exists
-        params: !opts.paramsSerializer ? opts.query : undefined,
+        params: opts.paramsSerializer ? opts.query : undefined,
         url,
       });
 
-- 
2.51.2