diff --git a/hashtree.py b/hashtree.py
old mode 100644
new mode 100755
--- a/hashtree.py
+++ b/hashtree.py
@@ -12,6 +12,7 @@ class HashTree:
     self.store=[None]*(leafCount*2-1)
     self.leafStart=leafCount-1
     self.index=self.leafStart
+    self.leafCount=leafCount
     
   @classmethod
   def fromFile(cls,fd):