diff --git a/glances/glances.py b/glances/glances.py
index 131d1792..bf648652 100644
--- a/glances/glances.py
+++ b/glances/glances.py
@@ -150,6 +150,9 @@ diskio_tag = True
 fs_tag = True
 process_tag = True
 
+# Global moved outside main for unit tests
+last_update_times = {}
+
 
 # Classes
 #========