diff --git a/utils.py b/utils.py
index ec8ef83..3c87390 100644
--- a/utils.py
+++ b/utils.py
@@ -2,7 +2,7 @@
 from daal.data_management import HomogenNumericTable, BlockDescriptor_Float64, readOnly
 
 def getArrayFromNT(table, nrows=0):
-    bd = BlockDescriptor()
+    bd = BlockDescriptor_Float64()
     if nrows == 0:
         nrows = table.getNumberOfRows()
     table.getBlockOfRows(0, nrows, readOnly, bd)