diff --git a/requirements.txt b/requirements.txt
index b3d291c7..9455c56e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@ aiohttp==3.8.1
 aiohttp-cors==0.7.0
 asyncpg==0.25.0
 jsonschema==4.4.0
-Cython==0.29.26
+Cython==0.29.27
 cyvcf2==0.30.14
 uvloop==0.16.0
 aiocache==0.11.1
diff --git a/setup.py b/setup.py
index d1ab610b..6e865489 100644
--- a/setup.py
+++ b/setup.py
@@ -52,7 +52,7 @@
         "vcf": [
             "numpy==1.22.1",
             "cyvcf2==0.30.14",
-            "Cython==0.29.26",
+            "Cython==0.29.27",
         ],
         "test": [
             "coverage==6.3",