diff --git a/.pr_agent.toml b/.pr_agent.toml
index b24df265..f8fd93ea 100644
--- a/.pr_agent.toml
+++ b/.pr_agent.toml
@@ -1,9 +1,11 @@
 [config]
 git_provider = "github"
+fallback_models = ["gpt-5.4-mini"]
 publish_output = true
 publish_output_progress = false
 response_language = "en-US"
-max_model_tokens = 32000
+max_model_tokens = 131072
+custom_model_max_tokens = 131072
 large_patch_policy = "clip"
 temperature = 0.1
 
diff --git a/tests/unit/scripts/github/ai-review-workflow.test.ts b/tests/unit/scripts/github/ai-review-workflow.test.ts
index f32ada6d..6e1c8573 100644
--- a/tests/unit/scripts/github/ai-review-workflow.test.ts
+++ b/tests/unit/scripts/github/ai-review-workflow.test.ts
@@ -38,6 +38,8 @@ describe('PR-Agent review lane migration', () => {
 
     expect(config).toContain('[config]');
     expect(config).toContain('git_provider = "github"');
+    expect(config).toContain('fallback_models = ["gpt-5.4-mini"]');
+    expect(config).toContain('custom_model_max_tokens = 131072');
     expect(config).toContain('[pr_reviewer]');
     expect(config).not.toContain('auto_review = true');
     expect(config).not.toContain('claude-code-action');