Set SESSION_COOKIE_SECURE=True for live.

app/its_dangerous_session.py

@@ -47,4 +47,4 @@ class ItsdangerousSessionInterface(SessionInterface):
         val = self.get_serializer(app).dumps(dict(session))
         response.set_cookie(app.session_cookie_name, val,
                             expires=expires, httponly=True,
-                            domain=domain)
+                            domain=domain, secure=app.config.get('SESSION_COOKIE_SECURE'))

config.py

@@ -56,6 +56,8 @@ class Test(Development):
 class Live(Config):
     DEBUG = False
     HTTP_PROTOCOL = 'https'
+    SESSION_COOKIE_SECURE = True
+
 
 configs = {
     'live': Live,