diff --git a/pytools/__init__.py b/pytools/__init__.py
index 57e33787e7660dd15729fd633d1d892e21946825..c096e99ff65b8dd0c852275ef4b82a2fea2d5ad9 100644
--- a/pytools/__init__.py
+++ b/pytools/__init__.py
@@ -315,12 +315,18 @@ class Record(RecordWithoutPickling):
 
 class ImmutableRecordWithoutPickling(RecordWithoutPickling):
     "Hashable record. Does not explicitly enforce immutability."
+    def __init__(self, *args, **kwargs):
+        RecordWithoutPickling.__init__(self, *args, **kwargs)
+        self._cached_hash = None
 
     def __hash__(self):
-        return hash(
+        if self._cached_hash is None:
+            self._cached_hash = hash(
                 (type(self),) + tuple(getattr(self, field)
                     for field in self.__class__.fields))
 
+        return self._cached_hash
+
 
 class ImmutableRecord(ImmutableRecordWithoutPickling, Record):
     pass