diff --git a/src/core/contentstack/client.ts b/src/core/contentstack/client.ts
index d476116..1349019 100644
--- a/src/core/contentstack/client.ts
+++ b/src/core/contentstack/client.ts
@@ -113,10 +113,12 @@ export default class ContentstackClient {
     try {
       const response = await this.instance.get('/content_types', {
         params: {
-          api_key: api_key,
           include_count: true,
           include_global_field_schema: includeGlobalFields,
         },
+        headers: {
+          api_key,
+        },
       })
 
       return response.data