diff --git a/pytools/persistent_dict.py b/pytools/persistent_dict.py
index 8fd6f849a87c410757022f740ccf2be1f261bc72..8d8d06ddf33ecd475d108bd7ef595055f87d6fb9 100644
--- a/pytools/persistent_dict.py
+++ b/pytools/persistent_dict.py
@@ -238,9 +238,14 @@ class KeyBuilder:
             try:
                 method = getattr(self, "update_for_"+tname)
             except AttributeError:
-                # Handling numpy >= 1.20, for which
-                # type(np.dtype("float32")) -> "dtype[float32]"
-                if tname.startswith("dtype[") and "numpy" in sys.modules:
+                if (
+                        # Handling numpy >= 1.20, for which
+                        # type(np.dtype("float32")) -> "dtype[float32]"
+                        tname.startswith("dtype[")
+                        # Handling numpy >= 1.25, for which
+                        # type(np.dtype("float32")) -> "Float32DType"
+                        or tname.endswith("DType")
+                        ) and "numpy" in sys.modules:
                     import numpy as np
                     if isinstance(key, np.dtype):
                         method = self.update_for_specific_dtype
diff --git a/test/test_persistent_dict.py b/test/test_persistent_dict.py
index a64b71833379b5fe4d4593a98966fddde50564fc..59dd49139aaf827995ce0fde9e263e34fccaa79c 100644
--- a/test/test_persistent_dict.py
+++ b/test/test_persistent_dict.py
@@ -7,8 +7,8 @@ from enum import Enum, IntEnum
 import pytest
 
 from pytools.persistent_dict import (
-    CollisionWarning, NoSuchEntryError, PersistentDict, ReadOnlyEntryError,
-    WriteOncePersistentDict)
+    CollisionWarning, KeyBuilder, NoSuchEntryError, PersistentDict,
+    ReadOnlyEntryError, WriteOncePersistentDict)
 from pytools.tag import Tag, tag_dataclass
 
 
@@ -372,6 +372,14 @@ def test_write_once_persistent_dict_clear():
         shutil.rmtree(tmpdir)
 
 
+def test_dtype_hashing():
+    np = pytest.importorskip("numpy")
+
+    keyb = KeyBuilder()
+    assert keyb(np.float32) == keyb(np.float32)
+    assert keyb(np.dtype(np.float32)) == keyb(np.dtype(np.float32))
+
+
 if __name__ == "__main__":
     if len(sys.argv) > 1:
         exec(sys.argv[1])