diff --git a/server/web2py/applications/vidjil/controllers/config.py b/server/web2py/applications/vidjil/controllers/config.py
index 4bacbd626a6aa570a1b4b7cbddaad11d6c7fb129..94ab414925f7e4d2f3938e6f0c92b8263c9198ae 100644
--- a/server/web2py/applications/vidjil/controllers/config.py
+++ b/server/web2py/applications/vidjil/controllers/config.py
@@ -49,10 +49,12 @@ def add_form():
             error += field+" needed, "
 
     ## test if classification id exist
-    classification = db(db.classification.id ==  request.vars["config_classification"]).select()
-    if len(classification) == 0:
-        error += "classification id don't exist, "
-
+    if  request.vars["config_classification"] != "-1":
+        classification = db(db.classification.id ==  request.vars["config_classification"]).count()
+        if classification == 0:
+            error += "classification id don't exist, "
+    else :
+        request.vars["config_classification"] = None
 
     if error=="" :
         
@@ -111,9 +113,13 @@ def edit_form():
             error += field+" needed, "
     
     ## test if classification id exist
-    classification = db(db.classification.id ==  request.vars["config_classification"]).select()
-    if len(classification) == 0:
-        error += "classification id don't exist, "
+    if  request.vars["config_classification"] != "-1":
+        classification = db(db.classification.id ==  request.vars["config_classification"]).count()
+        if classification == 0:
+            error += "classification id don't exist, "
+    else :
+        request.vars["config_classification"] = None
+
 
     if error=="" :
 
diff --git a/server/web2py/applications/vidjil/views/config/add.html b/server/web2py/applications/vidjil/views/config/add.html
index 356a06fb37f882e8ac8a8f36dff4d5186c3a0356..d188ceeb9e2f09f3f4d2425693f76ae523387df1 100644
--- a/server/web2py/applications/vidjil/views/config/add.html
+++ b/server/web2py/applications/vidjil/views/config/add.html
@@ -11,6 +11,8 @@
             <tr>
                 <td> <label for="config_classification" id="config_classification__label">classification: </label> </td>
                 <td><select id="config_classification" name="config_classification">
+                        <option value="-1" title="No classification">---</option>
+
                         {{for class_elt in classification: }}
                             <option value="{{=class_elt.id}}" title="{{=class_elt.info}}">{{=class_elt.name}}</option>
                         {{pass}}
diff --git a/server/web2py/applications/vidjil/views/config/edit.html b/server/web2py/applications/vidjil/views/config/edit.html
index 7f08115100035c5024214a0aa49fa8acb6746a4b..17b9220642ee4fc597c85f842077445919f5d40b 100644
--- a/server/web2py/applications/vidjil/views/config/edit.html
+++ b/server/web2py/applications/vidjil/views/config/edit.html
@@ -16,6 +16,8 @@ info = db.config[request.vars["id"]]
             <tr>
                 <td> <label for="config_classification" id="config_classification__label">classification: </label> </td>
                 <td><select id="config_classification" name="config_classification">
+                    <option value="-1" {{if None == info.classification:}}selected="selected"{{pass}} title="no classification">---</option>
+
                         {{for class_elt in classification: }}
                             <option value="{{=class_elt.id}}" {{if class_elt.id == info.classification:}}selected="selected"{{pass}} title="{{=class_elt.info}}">{{=class_elt.name}}</option>
                         {{pass}}