diff --git a/pyproject.toml b/pyproject.toml
index 7b0f59c..9154864 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -128,7 +128,7 @@ dev = [
     "bump-my-version>=1.2.0,<2.0.0",
     "coverage>=7.13.0,<8.0.0",
     "diffrax>=0.7.0,<0.8.0",
-    "isort>=7.0.0,<8.0.0",
+    "isort>=7.0.0,<9.0.0",
     "jupyterlab>=4.5.0,<5.0.0",
     "matplotlib>=3.10.0,<4.0.0",
     "mkdocs-autorefs>=1.4.0,<2.0.0",