diff --git a/pyproject.toml b/pyproject.toml
index 33c962a8b..731898f51 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,7 @@ authors = [
 requires-python = ">=3.12"
 dependencies = [
     "numpy>=2.0.0",
-    'cython>=0.29.21,<3.1.4',
+    'cython>=0.29.21',
     'sympy>=1.2',
     'pyparsing>=3,!=3.2.4',
     'jinja2>=2.7',