diff --git a/src/greenbutton_objects/resources.py b/src/greenbutton_objects/resources.py
index 1195988..0f16b02 100644
--- a/src/greenbutton_objects/resources.py
+++ b/src/greenbutton_objects/resources.py
@@ -56,7 +56,7 @@ def __init__(self, entry, usagePoints=[], readingTypes=[], intervalBlocks=[]):
                 self.setReadingType(rt)
         for ib in intervalBlocks:
             if self.isParentOf(ib):
-                self.addIntervalBlock(r)
+                self.addIntervalBlock(ib)
 
     @property
     def intervalReadings(self):