My mistake

docs/changelog.rst

@@ -30,7 +30,7 @@ Changelog
 * Fix timezones in DateTimeLine
 * Rename in Style foreground_light as foreground_strong
 * Rename in Style foreground_dark as foreground_subtle
-* Add a ``render_data_uri`` method
+* Add a ``render_data_uri`` method (#237)
 
 1.7.0
 =====

pygal/graph/public.py

@@ -98,7 +98,7 @@ class PublicApi(BaseGraph):
         # Force protocol as data uri have none
         kwargs.setdefault('force_uri_protocol', 'https')
         return "data:image/svg+xml;charset=utf-8;base64,%s" % (
-            base64.urlsafe_b64encode(
+            base64.b64encode(
                 self.render(**kwargs)
             ).decode('utf-8').replace('\n', '')
         )