diff --git a/sumpy/tools.py b/sumpy/tools.py
index 642366839586dd498069078a7ddd99ef2fcb5638..bf57b0fb0c83021d662a59e774d5154d9554c0f1 100644
--- a/sumpy/tools.py
+++ b/sumpy/tools.py
@@ -336,6 +336,7 @@ class BlockIndexRanges(object):
         self.indices = indices
         self.ranges = ranges
 
+    @property
     @memoize_method
     def _ranges(self):
         with cl.CommandQueue(self.cl_context) as queue: