diff --git a/aider/models.py b/aider/models.py
index 8c4a0c3ea..e275c907e 100644
--- a/aider/models.py
+++ b/aider/models.py
@@ -72,6 +72,7 @@ claude-3-sonnet-20240229
 claude-3-5-sonnet-20240620
 claude-3-5-sonnet-20241022
 claude-sonnet-4-20250514
+claude-opus-4-20250514
 """
 
 ANTHROPIC_MODELS = [ln.strip() for ln in ANTHROPIC_MODELS.splitlines() if ln.strip()]
diff --git a/aider/onboarding.py b/aider/onboarding.py
index 0321c0d63..9b6abd54b 100644
--- a/aider/onboarding.py
+++ b/aider/onboarding.py
@@ -55,9 +55,9 @@ def try_to_select_default_model():
         # Check if the user is on a free tier
         is_free_tier = check_openrouter_tier(openrouter_key)
         if is_free_tier:
-            return "openrouter/google/gemini-2.5-pro-exp-03-25:free"
+            return "openrouter/deepseek/deepseek-r1:free"
         else:
-            return "openrouter/anthropic/claude-3.7-sonnet"
+            return "openrouter/anthropic/claude-sonnet-4"
 
     # Select model based on other available API keys
     model_key_pairs = [