diff --git a/notes_tools/df_marks_manip.py b/notes_tools/df_marks_manip.py
index cb68f5f..55cd4d3 100644
--- a/notes_tools/df_marks_manip.py
+++ b/notes_tools/df_marks_manip.py
@@ -8,11 +8,10 @@ from math import ceil
 # Values manipulations
 
 def round_half_point(val):
-    return 0.5 * ceil(2.0 * val)
-    #try:
-    #    return 0.5 * ceil(2.0 * val)
-    #except ValueError:
-    #    return val
+    try:
+        return 0.5 * ceil(2.0 * val)
+    except ValueError:
+        return val
 
 latex_caract = ["\\NoRep", "\\RepZ", "\\RepU", "\\RepD", "\\RepT"]
 def note_to_rep(x):
diff --git a/notes_tools/test/test_df_marks_manip.py b/notes_tools/test/test_df_marks_manip.py
index b2d7985..2b9058e 100644
--- a/notes_tools/test/test_df_marks_manip.py
+++ b/notes_tools/test/test_df_marks_manip.py
@@ -12,6 +12,7 @@ def test_round_half_point():
     assert df_marks_manip.round_half_point(2.4) == 2.5
     assert df_marks_manip.round_half_point(2.6) == 3
     assert df_marks_manip.round_half_point(2.9) == 3
+    assert df_marks_manip.round_half_point(pandas.np.nan)
 
 def test_note_to_rep():
     d = {"Niveau": 1, "Note": 0}