diff --git a/Dockerfile b/Dockerfile
index 5303a07..3c099ab 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,12 +1,12 @@
-FROM node:current-alpine
+FROM node:15.4.0-alpine
 
 # reviewdog
 ENV REVIEWDOG_VERSION=v0.11.0
 
+# hadolint ignore=DL3006
+RUN apk --no-cache add git
+
 RUN wget -O - -q https://raw.githubusercontent.com/reviewdog/reviewdog/master/install.sh| sh -s -- -b /usr/local/bin/ ${REVIEWDOG_VERSION}
-RUN apk --update add git && \
-    rm -rf /var/lib/apt/lists/* && \
-    rm /var/cache/apk/*
 
 COPY entrypoint.sh /entrypoint.sh