diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index afd45c0..ffba5d7 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -22,7 +22,7 @@ jobs:
     - name: Install python dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install 'Cython<3' 'tox<4'
+        pip install 'Cython' 'tox<4'
 
     - name: Run unittest
       run: |
diff --git a/greenify.pyx b/greenify.pyx
index 5bacf70..3b34658 100644
--- a/greenify.pyx
+++ b/greenify.pyx
@@ -29,7 +29,7 @@ cdef extern from "hook_greenify.h":
 
     void* greenify_patch_lib(const char* library_filename, greenified_function_t fn)
 
-cdef int wait_gevent(greenify_watcher* watchers, int nwatchers, int timeout_in_ms) with gil:
+cdef int wait_gevent(greenify_watcher* watchers, int nwatchers, int timeout_in_ms) noexcept with gil:
     cdef int fd, event
     cdef float timeout_in_s
     cdef int i
diff --git a/req.txt b/req.txt
index 4dc4307..31c5616 100644
--- a/req.txt
+++ b/req.txt
@@ -1,2 +1,2 @@
-cython >= 0.18, < 3
+cython
 gevent
diff --git a/setup.py b/setup.py
index 7b76a75..a185fe5 100644
--- a/setup.py
+++ b/setup.py
@@ -1,7 +1,7 @@
 from glob import glob
 from setuptools import setup, Extension
 
-version = "0.4.1"
+version = "0.4.2"
 
 
 def readme():
@@ -41,7 +41,7 @@ def readme():
     author_email="tianzhongbo@douban.com",
     url="https://github.com/douban/greenify",
     download_url="https://github.com/douban/greenify/archive/%s.tar.gz" % version,
-    setup_requires=["Cython >= 0.18, < 3"],
+    setup_requires=["Cython"],
     install_requires=["gevent"],
     ext_modules=[
         Extension(