diff --git a/packages/core/src/core/client.ts b/packages/core/src/core/client.ts
index afddb2df..d6a30c94 100644
--- a/packages/core/src/core/client.ts
+++ b/packages/core/src/core/client.ts
@@ -243,6 +243,7 @@ export class GeminiClient {
         ? {
             ...this.generateContentConfig,
             thinkingConfig: {
+              thinkingBudget: -1,
               includeThoughts: true,
             },
           }