diff --git a/loopy/version.py b/loopy/version.py
index 8516ce006bde8b8616172a72a766ec86dfcd44f1..02244f55d0dbf207a4641c3ebf6cc33b536f0421 100644
--- a/loopy/version.py
+++ b/loopy/version.py
@@ -32,4 +32,4 @@ except ImportError:
 else:
     _islpy_version = islpy.version.VERSION_TEXT
 
-DATA_MODEL_VERSION = "v63-islpy%s" % _islpy_version
+DATA_MODEL_VERSION = "v64-islpy%s" % _islpy_version