diff --git a/Pipfile b/Pipfile
index 20ae0a5..917c21d 100644
--- a/Pipfile
+++ b/Pipfile
@@ -4,7 +4,7 @@ url = "https://pypi.org/simple"
 verify_ssl = true
 
 [packages]
-Cython = "*"
+Cython = "<3"
 Jinja2 = "*"
 black = "*"
 flake8 = "*"
diff --git a/pyproject.toml b/pyproject.toml
index fd9aa9d..c829d6d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools", "wheel", "pkgconfig", "cython"]
+requires = ["setuptools", "wheel", "pkgconfig", "cython<3"]
 
 [tool.pytest.ini_options]
-asyncio_mode = "auto"
\ No newline at end of file
+asyncio_mode = "auto"
diff --git a/requirements.txt b/requirements.txt
index d495b72..ccda7ce 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 jinja2
 black
-cython
+cython<3
 flake8
 setuptools
 pkgconfig
diff --git a/tox.ini b/tox.ini
index 6b08b42..de20c96 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py37,py38,py39,py310
+envlist = py37,py38,py39,py310,py311
 skipsdist = True
 
 [testenv]
@@ -7,7 +7,7 @@ deps=
     pkgconfig
     Jinja2
     pytest
-    cython
+    cython<3
 
 commands =
     python setup.py install