diff --git a/moulinette/authenticators/__init__.py b/moulinette/authenticators/__init__.py
index 57d1a785..65e88143 100644
--- a/moulinette/authenticators/__init__.py
+++ b/moulinette/authenticators/__init__.py
@@ -93,8 +93,8 @@ class BaseAuthenticator(object):
             try:
                 # Extract id and hash from token
                 s_id, s_hash = token
-            except TypeError:
-                logger.error("unable to extract token parts from '%s'", token)
+            except TypeError as e:
+                logger.error("unable to extract token parts from '%s' because '%s'", token, e)
                 if password is None:
                     raise MoulinetteError('error_see_log')
 
@@ -110,17 +110,19 @@ class BaseAuthenticator(object):
             self.authenticate(password)
         except MoulinetteError:
             raise
-        except:
-            logger.exception("authentication (name: '%s', vendor: '%s') fails",
-                             self.name, self.vendor)
+        except Exception as e:
+            logger.exception("authentication (name: '%s', vendor: '%s') fails because '%s'",
+                             self.name, self.vendor, e)
             raise MoulinetteError('unable_authenticate')
 
         # Store session
         if store_session:
             try:
                 self._store_session(s_id, s_hash, password)
-            except:
-                logger.exception("unable to store session")
+            except Exception as e:
+                import traceback
+                traceback.print_exc()
+                logger.exception("unable to store session because %s", e)
             else:
                 logger.debug("session has been stored")