diff --git a/src/sysprof/sysprof-normalized-series.c b/src/sysprof/sysprof-normalized-series.c
index d5240b68..9ba633a3 100644
--- a/src/sysprof/sysprof-normalized-series.c
+++ b/src/sysprof/sysprof-normalized-series.c
@@ -174,7 +174,12 @@ sysprof_normalized_series_items_changed (SysprofSeries *series,
   g_assert (G_IS_LIST_MODEL (model));
 
   if (removed > 0 || added > 0)
-    egg_bitset_splice (self->missing, position, removed, added);
+    {
+      egg_bitset_splice (self->missing, position, removed, added);
+
+      if (added > 0)
+        egg_bitset_add_range (self->missing, position, added);
+    }
 
   if (removed > 0)
     g_array_remove_range (self->values, position, removed);