diff --git a/openmc/arithmetic.py b/openmc/arithmetic.py
index 618c7c4a1a..3655ef2a3d 100644
--- a/openmc/arithmetic.py
+++ b/openmc/arithmetic.py
@@ -604,6 +604,10 @@ class AggregateFilter:
     def num_bins(self):
         return len(self.bins) if self.aggregate_filter else 0
 
+    @property
+    def shape(self):
+        return (self.num_bins,)
+
     @type.setter
     def type(self, filter_type):
         if filter_type not in _FILTER_TYPES: