diff --git a/src/lib/seam-http-request.ts b/src/lib/seam-http-request.ts
index 7f10e0cd..4b36050d 100644
--- a/src/lib/seam-http-request.ts
+++ b/src/lib/seam-http-request.ts
@@ -92,10 +92,7 @@ export class SeamHttpRequest<
   public get url(): URL {
     const { client } = this.#parent
 
-    const serializer =
-      typeof client.defaults.paramsSerializer === 'function'
-        ? client.defaults.paramsSerializer
-        : serializeUrlSearchParams
+    const serializer = getParamsSerializer(client.defaults.paramsSerializer)
 
     const origin = getUrlPrefix(client.defaults.baseURL ?? '')
 
@@ -256,6 +253,16 @@ export class SeamHttpRequest<
   }
 }
 
+const getParamsSerializer = (
+  paramsSerializer: Client['defaults']['paramsSerializer'],
+): ((params: Record<string, unknown>) => string) => {
+  if (typeof paramsSerializer === 'function') return paramsSerializer
+  if (typeof paramsSerializer?.serialize === 'function') {
+    return paramsSerializer.serialize
+  }
+  return serializeUrlSearchParams
+}
+
 /**
  * Reads the response data at the response key,
  * throwing a {@link SeamHttpInvalidResponseError} for a success response
diff --git a/test/seam/connect/seam-http-request.test.ts b/test/seam/connect/seam-http-request.test.ts
index d61c3f86..8ed8ea48 100644
--- a/test/seam/connect/seam-http-request.test.ts
+++ b/test/seam/connect/seam-http-request.test.ts
@@ -205,6 +205,36 @@ test.serial(
   },
 )
 
+test('SeamHttpRequest: url uses a custom function form paramsSerializer', async (t) => {
+  const { seed } = await getTestServer(t)
+  const seam = SeamHttp.fromApiKey(seed.seam_apikey1_token, {
+    endpoint: 'https://example.com',
+    axiosOptions: {
+      paramsSerializer: () => 'custom=function',
+    },
+  })
+
+  const { url } = seam.devices.get({ device_id: 'abc123' })
+
+  t.is(url.search, '?custom=function')
+})
+
+test('SeamHttpRequest: url uses a custom object form paramsSerializer', async (t) => {
+  const { seed } = await getTestServer(t)
+  const seam = SeamHttp.fromApiKey(seed.seam_apikey1_token, {
+    endpoint: 'https://example.com',
+    axiosOptions: {
+      paramsSerializer: {
+        serialize: () => 'custom=object',
+      },
+    },
+  })
+
+  const { url } = seam.devices.get({ device_id: 'abc123' })
+
+  t.is(url.search, '?custom=object')
+})
+
 test('SeamHttpRequest: sends the request at most once when awaited more than once', async (t) => {
   const { seed, endpoint } = await getTestServer(t)
   const seam = SeamHttp.fromApiKey(seed.seam_apikey1_token, { endpoint })