diff --git a/bopytex/bopytex.py b/bopytex/bopytex.py
index 8ecd864..4da06f4 100755
--- a/bopytex/bopytex.py
+++ b/bopytex/bopytex.py
@@ -39,7 +39,7 @@ def setup():
         }
     pytex.update_export_dict(mapytex_tools)
 
-    pytex.add_filter("do_calculus", filters.do_calculus)
+    pytex.add_filter("calculus", filters.do_calculus)
 
 
 def get_working_dir(options):
@@ -65,8 +65,8 @@ def activate_printanswers(texfile):
         with open(output_fname, "w") as output_f:
             for line in input_f.readlines():
                 output_f.write(line.replace(
-                    r'%\printanswers',
-                    r'\printanswers'
+                    r'solution/print = false',
+                    r'solution/print = true',
                     ))
     return output_fname