diff --git a/apps/grpo/main.py b/apps/grpo/main.py
index cb97e08a3..10ea43d58 100644
--- a/apps/grpo/main.py
+++ b/apps/grpo/main.py
@@ -266,7 +266,12 @@ async def sample(self) -> dict[str, str] | None:
 
     @endpoint
     async def pad_token(self):
-        return self._tokenizer.pad_token_id
+        # Use pad_token_id if available, otherwise use eos_token_id
+        # Llama models don't have a pad token by default
+        if self._tokenizer.pad_token_id is not None:
+            return self._tokenizer.pad_token_id
+        else:
+            return self._tokenizer.eos_token_id
 
 
 async def drop_weights(version: int):