diff --git a/safeeyes/plugins/healthstats/plugin.py b/safeeyes/plugins/healthstats/plugin.py
index d4def48..5f97afe 100644
--- a/safeeyes/plugins/healthstats/plugin.py
+++ b/safeeyes/plugins/healthstats/plugin.py
@@ -55,7 +55,8 @@ def init(ctx, safeeyes_config, plugin_config):
             'total_resets': 0,
         }
 
-        session = context['session']['plugin'].get('healthstats', {}) or defaults
+        session = context['session']['plugin'].get('healthstats', {}).copy()
+        session.update(defaults)
         if 'no_of_breaks' in session:
             # Ignore old format session.
             session = defaults