diff --git a/docker/Dockerfile b/docker/Dockerfile
index a4bb300..1ef96f2 100644
--- a/docker/Dockerfile
+++ b/docker/Dockerfile
@@ -1,11 +1,10 @@
-FROM alpine:3.13.5
+FROM alpine:3.13.6
 
 EXPOSE 5353 8080
 
 ARG DYNDNSD_VERSION
 
 RUN apk --no-cache add openssl ca-certificates && \
-    apk upgrade apk-tools libcrypto1.1 libssl1.1 && \
     apk --no-cache add ruby ruby-etc ruby-io-console ruby-json ruby-webrick && \
     apk --no-cache add --virtual .build-deps linux-headers ruby-dev build-base tzdata && \
     gem install --no-document dyndnsd -v ${DYNDNSD_VERSION} && \
diff --git a/docker/ci/Dockerfile b/docker/ci/Dockerfile
index d24794c..acacbf9 100644
--- a/docker/ci/Dockerfile
+++ b/docker/ci/Dockerfile
@@ -1,11 +1,10 @@
-FROM alpine:3.13.5
+FROM alpine:3.13.6
 
 EXPOSE 5353 8080
 
 COPY pkg/dyndnsd-*.gem /tmp/dyndnsd.gem
 
 RUN apk --no-cache add openssl ca-certificates && \
-    apk upgrade apk-tools libcrypto1.1 libssl1.1 && \
     apk --no-cache add ruby ruby-etc ruby-io-console ruby-json ruby-webrick && \
     apk --no-cache add --virtual .build-deps linux-headers ruby-dev build-base tzdata && \
     gem install --no-document /tmp/dyndnsd.gem && \