diff --git a/bopytex/bopytex.py b/bopytex/bopytex.py
index f37f1a2..0b70f06 100755
--- a/bopytex/bopytex.py
+++ b/bopytex/bopytex.py
@@ -12,6 +12,7 @@ import logging
 from pathlib import Path
 import pytex
 from mapytex import Expression, Integer, Decimal, Polynomial, render
+import sympy
 import bopytex.filters as filters
 
 formatter = logging.Formatter("%(name)s :: %(levelname)s :: %(message)s")
@@ -31,6 +32,7 @@ def setup():
         "Integer": Integer,
         "Decimal": Decimal,
         "Polynom": Polynomial,
+        "sympy": sympy,
         # "Fraction": mapytex.Fraction,
         # "Equation": mapytex.Equation,
         # "random_str": mapytex.random_str,
@@ -157,7 +159,7 @@ def crazy_feed(*args, **kwrds):
 
 
 def clean(directory):
-    pytex.clean(directory, ["*.aux", "*.log", "*.out", "*.xsim"])
+    pytex.clean(directory, ["*.aux", "*.log", "*.out", "*.xsim", "*.tkzfonct.*"])
 
 
 def texcompile(filename):