1 files changed, 7 insertions, 7 deletions
diff --git a/pint/pint_eval.py b/pint/pint_eval.py
index d476eae..a2952ec 100644
--- a/pint/pint_eval.py
+++ b/pint/pint_eval.py
@@ -13,7 +13,7 @@ import operator
 import token as tokenlib
 from tokenize import TokenInfo
 
-from typing import Any
+from typing import Any, Optional, Union
 
 from .errors import DefinitionSyntaxError
 
@@ -82,9 +82,9 @@ class EvalTreeNode:
 
     def __init__(
         self,
-        left: EvalTreeNode | TokenInfo,
-        operator: TokenInfo | None = None,
-        right: EvalTreeNode | None = None,
+        left: Union[EvalTreeNode, TokenInfo],
+        operator: Optional[TokenInfo] = None,
+        right: Optional[EvalTreeNode] = None,
     ):
         self.left = left
         self.operator = operator
@@ -114,8 +114,8 @@ class EvalTreeNode:
             ],
             Any,
         ],
-        bin_op: dict[str, BinaryOpT] | None = None,
-        un_op: dict[str, UnaryOpT] | None = None,
+        bin_op: Optional[dict[str, BinaryOpT]] = None,
+        un_op: Optional[dict[str, UnaryOpT]] = None,
     ):
         """Evaluate node.
 
@@ -291,7 +291,7 @@ def _build_eval_tree(
 
 def build_eval_tree(
     tokens: Iterable[TokenInfo],
-    op_priority: dict[str, int] | None = None,
+    op_priority: Optional[dict[str, int]] = None,
 ) -> EvalTreeNode:
     """Build an evaluation tree from a set of tokens.