diff --git a/environments/benchmarks/yc_bench/default.yaml b/environments/benchmarks/yc_bench/default.yaml
index 871c1eaa8..4396c00ab 100644
--- a/environments/benchmarks/yc_bench/default.yaml
+++ b/environments/benchmarks/yc_bench/default.yaml
@@ -37,7 +37,7 @@ env:
 
 openai:
   base_url: "https://openrouter.ai/api/v1"
-  model_name: "anthropic/claude-sonnet-4-20250514"
+  model_name: "anthropic/claude-sonnet-4.6"
   server_type: "openai"
   health_check: false
   # api_key loaded from OPENROUTER_API_KEY in .env
diff --git a/environments/benchmarks/yc_bench/yc_bench_env.py b/environments/benchmarks/yc_bench/yc_bench_env.py
index 4965a559f..5b6bf9ad3 100644
--- a/environments/benchmarks/yc_bench/yc_bench_env.py
+++ b/environments/benchmarks/yc_bench/yc_bench_env.py
@@ -375,7 +375,7 @@ class YCBenchEvalEnv(HermesAgentBaseEnv):
         server_configs = [
             APIServerConfig(
                 base_url="https://openrouter.ai/api/v1",
-                model_name="anthropic/claude-sonnet-4-20250514",
+                model_name="anthropic/claude-sonnet-4.6",
                 server_type="openai",
                 api_key=os.getenv("OPENROUTER_API_KEY", ""),
                 health_check=False,