diff --git a/nilmdb/utils/diskusage.py b/nilmdb/utils/diskusage.py
index 0eea832..a7a2c32 100644
--- a/nilmdb/utils/diskusage.py
+++ b/nilmdb/utils/diskusage.py
@@ -21,7 +21,8 @@ def du(path):
     errors that might occur if we encounter broken symlinks or
     files in the process of being removed."""
     try:
-        size = os.path.getsize(path)
+        st = os.stat(path)
+        size = st.st_blocks * st.st_blksize
         if os.path.isdir(path):
             for thisfile in os.listdir(path):
                 filepath = os.path.join(path, thisfile)