diff --git a/assume/common/outputs.py b/assume/common/outputs.py
index b79abd54..ce8d8603 100644
--- a/assume/common/outputs.py
+++ b/assume/common/outputs.py
@@ -568,9 +568,9 @@ def get_sum_reward(self):
         query = text(
             f"select unit, SUM(reward) FROM rl_params where simulation='{self.simulation_id}' GROUP BY unit"
         )
-
-        with self.db.begin() as db:
-            rewards_by_unit = db.execute(query).fetchall()
+        if self.db is not None:
+            with self.db.begin() as db:
+                rewards_by_unit = db.execute(query).fetchall()
 
         # convert into a numpy array
         rewards_by_unit = [r[1] for r in rewards_by_unit]
diff --git a/pyproject.toml b/pyproject.toml
index 4ea505c1..bb18c2aa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,6 +26,7 @@ classifiers=[
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
 ]
 requires-python = ">=3.10"
 dependencies = [