diff --git a/notes_tools/tools/evaluation.py b/notes_tools/tools/evaluation.py
index 76640a4..d109c7d 100644
--- a/notes_tools/tools/evaluation.py
+++ b/notes_tools/tools/evaluation.py
@@ -208,7 +208,7 @@ class Classe(object):
         level_heatmap = sns.heatmap(pv.T)
 
         level_heatmap.hlines(exercice_sep, 
-                *self._level_heatmap.get_xlim(),
+                *level_heatmap.get_xlim(),
                 colors = "orange",
                 )
         return level_heatmap