diff --git a/examples/xml/pincell/settings.xml b/examples/xml/pincell/settings.xml
index d9fab5b633..7b0a985f10 100644
--- a/examples/xml/pincell/settings.xml
+++ b/examples/xml/pincell/settings.xml
@@ -5,7 +5,7 @@
   <run_mode>eigenvalue</run_mode>
   <batches>10</batches>
   <inactive>5</inactive>
-  <particles>100000</particles>
+  <particles>1000</particles>
 
   <!-- The starting source is a uniform distribution over the entire pin
        cell. Note that since this is effectively a 2D model, the z coordinates
diff --git a/openmc/lib/core.py b/openmc/lib/core.py
index 0bfdb457b4..f26ddc5259 100644
--- a/openmc/lib/core.py
+++ b/openmc/lib/core.py
@@ -20,7 +20,8 @@ class _Bank(Structure):
                 ('E', c_double),
                 ('wgt', c_double),
                 ('delayed_group', c_int),
-                ('particle', c_int)]
+                ('particle', c_int),
+                ('parent_id', c_int64)]
 
 
 # Define input type for numpy arrays that will be passed into C++ functions