diff --git a/src/pyhf/tensor/numpy_backend.py b/src/pyhf/tensor/numpy_backend.py
index 4529c5a7e6..3b7dec18a9 100644
--- a/src/pyhf/tensor/numpy_backend.py
+++ b/src/pyhf/tensor/numpy_backend.py
@@ -7,7 +7,7 @@
 
 from pyhf.typing import TensorBackend, Shape
 
-from typing import TypeVar, Callable, Literal, Sequence, Generic, Mapping
+from typing import TypeVar, Callable, Literal, Sequence, Generic, Mapping, Union
 from numpy.typing import (
     NDArray,
     NBitBase,
@@ -16,7 +16,7 @@
 )
 
 T = TypeVar("T", bound=NBitBase)
-Tensor = NDArray[np.number[T]] | NDArray[np.bool_]
+Tensor = Union[NDArray[np.number[T]], NDArray[np.bool_]]
 
 log = logging.getLogger(__name__)