diff --git a/dev-requirements.txt b/dev-requirements.txt
index f15af0f..c5a6e63 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1,5 +1,5 @@
 nose
-cython
+cython<3.0
 numpy
 pytest
 dateparser
diff --git a/pyproject.toml b/pyproject.toml
index b8c4fc3..a86863c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -3,6 +3,6 @@ requires = [
     "setuptools",
     "wheel",
 	"oldest-supported-numpy",
-    "cython"
+    "cython<3.0"
 ]
 build-backend = "setuptools.build_meta"
diff --git a/requirements-test.txt b/requirements-test.txt
index 54a1eb0..c5c9ff2 100644
--- a/requirements-test.txt
+++ b/requirements-test.txt
@@ -4,7 +4,7 @@ wheel
 flake8
 nose
 coverage
-cython
+cython<3.0
 numpy
 pytest
 dateparser