diff --git a/include/config.inc.example b/include/config.inc.example
index 584dd211c..d3024056c 100644
--- a/include/config.inc.example
+++ b/include/config.inc.example
@@ -63,4 +63,8 @@ define ("dbname","");
 // you can uncomment this
 // after replace NOALYSS_HOME by the path of the local installation of Noalyss
 // ini_alter("open_basedir", "/usr/bin:/tmp/:NOALYSS_HOME");
-  
\ No newline at end of file
+
+// In recent distribution linux, pdftk is a snap, you should set the path
+// for exporting document in PDF
+// $pdftk = /usr/bin/pdftk 
+// $pdftk = /snap/bin/pdftk 
diff --git a/include/constant.php b/include/constant.php
index a5f2119a1..748d26496 100644
--- a/include/constant.php
+++ b/include/constant.php
@@ -271,7 +271,7 @@ if ( ! file_exists($ps2pdf) )
 /**
  * Outil pour manipuler les PDF 
  */
-$pdftk='/snap/bin/pdftk';
+if ( ! isset ($pdftk)) { $pdftk ='/usr/bin/pdftk'; }
 if (file_exists($pdftk))
 {
     define ('PDFTK',$pdftk);  
diff --git a/include/lib/config_file.php b/include/lib/config_file.php
index 3074fbddb..fcdb6021d 100644
--- a/include/lib/config_file.php
+++ b/include/lib/config_file.php
@@ -227,7 +227,10 @@ function display_file_config($p_array,$from_setup=1,$p_os=1)
     print ("// define ('OVERRIDE_PARAM',1);\r\n");
     print ("// ini_set ('max_execution_time',240);\r\n");
     print ("// ini_set ('memory_limit','256M');\r\n");
-// 
+    print ("// In recent distribution linux, pdftk is a snap, you should set the path\r\n");
+    print ("// for exporting document in PDF\r\n");
+    print ("// \$pdftk = /usr/bin/pdftk \r\n");
+    print ("// \$pdftk = /snap/bin/pdftk \r\n");
 
 }
 /*!\brief create the config file