diff --git a/Dockerfile b/Dockerfile
index 5a84bfe5e4..d93839704f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -593,7 +593,7 @@ RUN prototool lint --protoc-bin-path=/toolchain/bin/protoc --protoc-wkt-path=/to
 
 # The markdownlint target performs linting on Markdown files.
 
-FROM node:15.8.0-alpine AS lint-markdown
+FROM node:15.9.0-alpine AS lint-markdown
 RUN apk add --no-cache findutils
 RUN npm i -g markdownlint-cli@0.23.2
 RUN npm i -g textlint@11.7.6