diff --git a/requirements.dev.txt b/requirements.dev.txt
index bc15a53d5552a474eb89082a59976daeb68199ed..6bd266546e3604783f54e259bd738c1a9e7e1f5d 100644
--- a/requirements.dev.txt
+++ b/requirements.dev.txt
@@ -1,5 +1,5 @@
 flake8==3.7.7
-Cython==0.29.7
+Cython==0.29.9
 nose==1.3.7
 pylint==1.9.4
 pytest==4.4.1