diff --git a/devices.py b/devices.py
index 8c3ca29..1071f84 100644
--- a/devices.py
+++ b/devices.py
@@ -310,7 +310,9 @@ class FrappyConfig(Device):
 
     def show_config(self, allcfg, full=False):
         proposed, overview = self.to_consider(allcfg)
-        if full == 'auto' and overview != self._previous_shown or full is True:
+        if full == 'auto':
+            full = self._previous_shown is not None and overview != self._previous_shown
+        if full:
             for line in overview:
                 session.log.info('%s', line)
         # remove 'frappy.has_changed()' commands in script queue