diff --git a/plotter.py b/plotter.py
index 4af07f3..bbd5c12 100644
--- a/plotter.py
+++ b/plotter.py
@@ -341,10 +341,10 @@ class Plotter(Aggregator, BaseProcessor):
 
             # Find plot save
             if from_cells or rule.kind == "cells":
-                if not os.exists(self.pp[run][num].cells_filename):
-                    self.pp[run][num].load_cells()
-                    self.pp[run][num].unload_cells()
-                    save = tables.open_file(self.pp[run][num].cells_filename)
+                if not os.path.exists(self.snaps[run][num].cells_filename):
+                    self.snaps[run][num].load_cells()
+                    self.snaps[run][num].unload_cells()
+                    save = tables.open_file(self.snaps[run][num].cells_filename)
             elif rule.kind == "snapshot":
                 save = tables.open_file(self.snaps[run][num].filename)
             else: