diff --git a/validphys2/src/validphys/utils.py b/validphys2/src/validphys/utils.py
index c4bdfde845..3471cfb954 100644
--- a/validphys2/src/validphys/utils.py
+++ b/validphys2/src/validphys/utils.py
@@ -19,7 +19,7 @@
 def make_hashable(obj: Any):
     # So that we don't infinitely recurse since frozenset and tuples
     # are Sequences.
-    if isinstance(obj, typing.Hashable):
+    if isinstance(obj, Hashable):
         return obj
     elif isinstance(obj, Mapping):
         return frozendict(obj)