diff --git a/include/constant.php b/include/constant.php
index de0dcbba4..24b0cf563 100644
--- a/include/constant.php
+++ b/include/constant.php
@@ -227,8 +227,8 @@ define ("FICHE_TYPE_MATERIAL",7);
  * ou
  *  unoconv -l -v -s localhost
  */
-define ('OFFICE','unoconv ');
-define ('GENERATE_PDF','YES');
+if ( ! defined ('OFFICE')) define ('OFFICE','');
+if ( ! defined ('GENERATE_PDF') ) define ('GENERATE_PDF','NO');
 
 /**
  * Pour conversion GIF en PDF
diff --git a/include/lib/config_file.php b/include/lib/config_file.php
index 92403f47b..580747aeb 100644
--- a/include/lib/config_file.php
+++ b/include/lib/config_file.php
@@ -201,6 +201,11 @@ function display_file_config($p_array,$from_setup=1,$p_os=1)
     print ( "// Fix an issue with PDF when exporting receipt in PDF in ANCGL"."\r\n");
     print ( '// define ("FIX_BROKEN_PDF","NO");');
     print ("\r\n");
+    print ("// Uncomment if you want to convert to PDF");
+    print ("// With the unoconv tool");
+    print ( "//define ('OFFICE','HOME=/tmp unoconv ');");
+    print ("\r\n");
+    printf("//define ('GENERATE_PDF','YES');");
     print ("\r\n");
     print ( "// Uncomment if you don't want "."\r\n");
     print ( "// to be informed when a new release is "."\r\n");