diff --git a/config.json b/config.json
index 4b3b089..46375fb 100644
--- a/config.json
+++ b/config.json
@@ -1,6 +1,6 @@
 {
   "task_model": "openrouter/google/gemini-2.5-pro",
-  "reflection_model": "openrouter/anthropic/claude-4-sonnet",
+  "reflection_model": "openrouter/anthropic/claude-sonnet-4",
   "max_tokens": 8000,
   "temperature": 0.1,
   "test_size": 50,
diff --git a/src/llm_judge/cli/run_gepa.py b/src/llm_judge/cli/run_gepa.py
index 30f904d..2c29e82 100644
--- a/src/llm_judge/cli/run_gepa.py
+++ b/src/llm_judge/cli/run_gepa.py
@@ -29,7 +29,7 @@ def parse_args():
         "--task-model", type=str, default="meta-llama/llama-3.3-70b-instruct"
     )
     parser.add_argument(
-        "--reflection-model", type=str, default="anthropic/claude-4-sonnet"
+        "--reflection-model", type=str, default="anthropic/claude-sonnet-4"
     )
     parser.add_argument(
         "--no-separate-reflection",