diff --git a/loopy/target/__init__.py b/loopy/target/__init__.py
index 5d5743bae322fc59c989cafd85122c8ca619c422..7e307ef8bdd4d89e24b26dbacf39733ab3350307 100644
--- a/loopy/target/__init__.py
+++ b/loopy/target/__init__.py
@@ -55,6 +55,7 @@ class TargetBase(object):
     comparison_fields = ()
 
     def update_persistent_hash(self, key_hash, key_builder):
+        key_hash.update(type(self).__name__.encode())
         for field_name in self.hash_fields:
             key_builder.rec(key_hash, getattr(self, field_name))