diff --git a/conservancy_beancount/reports/query.py b/conservancy_beancount/reports/query.py
index 7c90cccf11b5e942caf2568bf8558ae7fd459045..a5c2bdc7ed1bf09b6cf658d2d4cfbd84a7442810 100644
--- a/conservancy_beancount/reports/query.py
+++ b/conservancy_beancount/reports/query.py
@@ -394,7 +394,7 @@ class AggregateSet(bc_query_compile.EvalAggregator):
     def update(self, store: Store, context: PostingContext) -> None:
         """Update existing storage with new result data."""
         value, = self.eval_args(context)
-        if isinstance(value, Sequence) and not isinstance(value, (str, tuple)):
+        if isinstance(value, Iterable) and not isinstance(value, (str, tuple)):
             store[self.handle].update(value)
         else:
             store[self.handle].add(value)