diff --git a/conservancy_beancount/reports/core.py b/conservancy_beancount/reports/core.py
index 1154b4c..5e27169 100644
--- a/conservancy_beancount/reports/core.py
+++ b/conservancy_beancount/reports/core.py
@@ -174,8 +174,8 @@ class Balance(Mapping[str, data.Amount]):
         if tolerance is None:
             tolerance = self.tolerance
         return type(self)(
-            amount for amount in self.values()
-            if abs(amount.number) >= tolerance
+            (amount for amount in self.values() if abs(amount.number) >= tolerance),
+            tolerance,
         )
 
     @staticmethod