diff --git a/attributs.py b/attributs.py
index 60424c0..0d12bfe 100644
--- a/attributs.py
+++ b/attributs.py
@@ -1076,7 +1076,13 @@ class blacklist(Attr):
     python_type = dict
 
     def parse_value(self, blacklist):
-        bl_debut, bl_fin, bl_type, bl_comm = blacklist.split('$')
+        if isinstance(blacklist, self.python_type):
+            if set(blacklist.keys()).issuperset(['debut', 'fin', 'type', 'comm']):
+                bl_debut, bl_fin, bl_type, bl_comm = (blacklist['debut'], blacklist['fin'], blacklist['type'], blacklist['comm'])
+            else:
+                raise ValueError("A blacklist should contain the following keys : 'debut', 'fin', 'type', 'comm'")
+        else:
+            bl_debut, bl_fin, bl_type, bl_comm = blacklist.split('$')
         now = time.time()
         self.value = { 'debut' : bl_debut if bl_debut == '-' else int (bl_debut),
                        'fin' : bl_fin if bl_fin == '-' else int(bl_fin),