diff --git a/docker/nginx/Dockerfile b/docker/nginx/Dockerfile
index e8944c0..8ace35b 100644
--- a/docker/nginx/Dockerfile
+++ b/docker/nginx/Dockerfile
@@ -1,4 +1,4 @@
-FROM nginx:1.21.3-alpine
+FROM nginx:1.21.4-alpine
 
 RUN apk --no-cache add tzdata && \
     cp /usr/share/zoneinfo/Asia/Tokyo /etc/localtime && \