diff --git a/weboob/backends/meteofrance/browser.py b/weboob/backends/meteofrance/browser.py
index 00e82920..54afe120 100644
--- a/weboob/backends/meteofrance/browser.py
+++ b/weboob/backends/meteofrance/browser.py
@@ -54,7 +54,7 @@ class MeteofranceBrowser(BaseBrowser):
         else:
             # Case 2: there is only one result, and the website send directly
             # the browser on the forecast page:
-            return self.page.get_city()
+            return [self.page.get_city()]
 
     def iter_forecast(self, city_id):
         self.location(self.WEATHER_URL.format(cityid=city_id))
diff --git a/weboob/tools/application/formatters/iformatter.py b/weboob/tools/application/formatters/iformatter.py
index 77043e47..ec7759fd 100644
--- a/weboob/tools/application/formatters/iformatter.py
+++ b/weboob/tools/application/formatters/iformatter.py
@@ -97,7 +97,7 @@ class IFormatter(object):
         @param selected_fields  [tuple] fields to display. If None, all fields are selected
         @return  a string of the formatted object
         """
-        assert isinstance(obj, (dict, CapBaseObject, tuple))
+        assert isinstance(obj, (dict, CapBaseObject, tuple)), 'Object is unexpected type "%r"' % obj
 
         if isinstance(obj, dict):
             item = obj