diff --git a/moulinette/actionsmap.py b/moulinette/actionsmap.py
index 11f7e2be..da2df8e0 100644
--- a/moulinette/actionsmap.py
+++ b/moulinette/actionsmap.py
@@ -563,6 +563,8 @@ class ActionsMap(object):
                 )
                 func = getattr(mod, func_name)
             except (AttributeError, ImportError):
+                import traceback
+                traceback.print_exc()
                 logger.exception("unable to load function %s.%s", namespace, func_name)
                 raise MoulinetteError("error_see_log")
             else:
diff --git a/moulinette/interfaces/__init__.py b/moulinette/interfaces/__init__.py
index 4f2e33dd..08b0cb98 100644
--- a/moulinette/interfaces/__init__.py
+++ b/moulinette/interfaces/__init__.py
@@ -361,6 +361,8 @@ class _CallbackAction(argparse.Action):
             mod = __import__(mod_name, globals=globals(), level=0, fromlist=[func_name])
             func = getattr(mod, func_name)
         except (AttributeError, ImportError):
+            import traceback
+            traceback.print_exc()
             raise ValueError("unable to import method {0}".format(self.callback_method))
         self._callback = func