diff --git a/reasoning_gym/games/countdown.py b/reasoning_gym/games/countdown.py
index 0551824d..87cd216e 100644
--- a/reasoning_gym/games/countdown.py
+++ b/reasoning_gym/games/countdown.py
@@ -178,7 +178,7 @@ class CountdownDataset(ProceduralDataset):
         for sym_name, num_str in replacements:
             expr_str = expr_str.replace(sym_name, num_str)
 
-        return expr, numbers, syms
+        return expr, numbers, syms, expr_str
 
     def _generate_expression(self, rng: Random) -> tuple[str, list[int], int]:
         """Generate a valid expression and its result