diff --git a/hugr-py/src/hugr/hugr.py b/hugr-py/src/hugr/hugr.py
index 7e74fe0b4..b4f70050a 100644
--- a/hugr-py/src/hugr/hugr.py
+++ b/hugr-py/src/hugr/hugr.py
@@ -4,7 +4,6 @@
 from enum import Enum
 from typing import (
     Iterable,
-    Self,
     Sequence,
     Protocol,
     Generic,
@@ -14,6 +13,8 @@
     ClassVar,
 )
 
+from typing_extensions import Self
+
 from hugr.serialization.serial_hugr import SerialHugr
 from hugr.serialization.ops import BaseOp, OpType as SerialOp
 import hugr.serialization.ops as sops
diff --git a/poetry.lock b/poetry.lock
index 24e529051..3112b9dd0 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -589,13 +589,13 @@ files = [
 
 [[package]]
 name = "typing-extensions"
-version = "4.11.0"
+version = "4.12.0"
 description = "Backported and Experimental Type Hints for Python 3.8+"
 optional = false
 python-versions = ">=3.8"
 files = [
-    {file = "typing_extensions-4.11.0-py3-none-any.whl", hash = "sha256:c1f94d72897edaf4ce775bb7558d5b79d8126906a14ea5ed1635921406c0387a"},
-    {file = "typing_extensions-4.11.0.tar.gz", hash = "sha256:83f085bd5ca59c80295fc2a82ab5dac679cbe02b9f33f7d83af68e241bea51b0"},
+    {file = "typing_extensions-4.12.0-py3-none-any.whl", hash = "sha256:b349c66bea9016ac22978d800cfff206d5f9816951f12a7d0ec5578b0a819594"},
+    {file = "typing_extensions-4.12.0.tar.gz", hash = "sha256:8cbcdc8606ebcb0d95453ad7dc5065e6237b6aa230a31e81d0f440c30fed5fd8"},
 ]
 
 [[package]]
@@ -621,4 +621,4 @@ test = ["covdefaults (>=2.3)", "coverage (>=7.2.7)", "coverage-enable-subprocess
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.10"
-content-hash = "487ddc7148ab4801c38871d976104e32eb884e91342ea1cdc05d2aa090489a0c"
+content-hash = "1238f0887779cfa07a16819569dcc29377cdf936b5e8c227fd5959250d1977f3"
diff --git a/pyproject.toml b/pyproject.toml
index 3138b5893..a67f62af5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -21,6 +21,9 @@ toml = "^0.10.0"
 [tool.poetry.group.hugr.dependencies]
 hugr = { path = "hugr-py", develop = true }
 
+
+[tool.poetry.dependencies]
+typing-extensions = "^4.12.0"
 [build-system]
 requires = ["poetry-core"]
 build-backend = "poetry.core.masonry.api"