diff --git a/srm_tools/stats.py b/srm_tools/stats.py
index b077368..81e8a28 100644
--- a/srm_tools/stats.py
+++ b/srm_tools/stats.py
@@ -8,6 +8,7 @@ class Stats():
 
     def __init__(self):
         self.load()
+        self.dirty = {}
 
     def load(self):
         self.data = DF.Flow(