diff --git a/infomentor/connector.py b/infomentor/connector.py
index c5d9d8c..cb49f27 100644
--- a/infomentor/connector.py
+++ b/infomentor/connector.py
@@ -247,7 +247,7 @@ class Infomentor(object):
         file.save_file(self._last_result.content)
         return file.fullfilename
 
-    def _build_url(self, path='', base=BASE_IM1):
+    def _build_url(self, path='', base=self.BASE_IM1):
         '''Builds a general infomentor (IM1) url'''
         return '{}/{}'.format(base, path)