diff --git a/Dockerfile b/Dockerfile
index a95ffb3..d313d8d 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -6,8 +6,8 @@ ARG CHECKSUM="5eee1bd1c23e3b9477a45532f1f36ae6178b43d571a9607e6953cef26d5df1e2"
 ARG OPENSSL_VERSION="1.1.1q"
 ARG OPENSSL_CHECKSUM="d7939ce614029cdff0b6c20f0e2e5703158a489a72b2507b8bd51bf8c8fd10ca"
 
-ARG ZLIB_VERSION="1.2.12"
-ARG ZLIB_CHECKSUM="91844808532e5ce316b3c010929493c0244f3d37593afd6de04f71821d5136d9"
+ARG ZLIB_VERSION="1.2.13"
+ARG ZLIB_CHECKSUM="b3a24de97a8fdbc835b9833169501030b8977031bcb54b3b3ac13740f846ab30"
 
 ADD https://nginx.org/download/nginx-$VERSION.tar.gz /tmp/nginx.tar.gz
 ADD https://www.openssl.org/source/openssl-$OPENSSL_VERSION.tar.gz /tmp/openssl.tar.gz