diff --git a/Dockerfile b/Dockerfile
index 94a5d4c..92d93de 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@ ARG             VCS_REF
 ARG             VERSION
 
 # build
-FROM            golang:1.16.5-alpine as builder
+FROM            golang:1.16.7-alpine as builder
 RUN             apk add --no-cache git gcc musl-dev make
 ENV             GO111MODULE=on
 WORKDIR         /go/src/moul.io/moulsay
@@ -14,7 +14,7 @@ COPY            . ./
 RUN             make install
 
 # minimalist runtime
-FROM            alpine:3.13.5
+FROM            alpine:3.14.1
 LABEL           org.label-schema.build-date=$BUILD_DATE \
                 org.label-schema.name="moulsay" \
                 org.label-schema.description="" \
diff --git a/go.mod b/go.mod
index 2b69a19..7dea2ab 100644
--- a/go.mod
+++ b/go.mod
@@ -4,6 +4,6 @@ go 1.16
 
 require (
 	github.com/eidolon/wordwrap v0.0.0-20161011182207-e0f54129b8bb
-	github.com/peterbourgon/ff/v3 v3.0.0
+	github.com/peterbourgon/ff/v3 v3.1.0
 	moul.io/asciimoul v1.1.0
 )
diff --git a/go.sum b/go.sum
index 9733e29..01f16ad 100644
--- a/go.sum
+++ b/go.sum
@@ -3,8 +3,8 @@ github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/eidolon/wordwrap v0.0.0-20161011182207-e0f54129b8bb h1:ioQwBmKdOCpMVS/bDaESqNWXIE/aw4+gsVtysCGMWZ4=
 github.com/eidolon/wordwrap v0.0.0-20161011182207-e0f54129b8bb/go.mod h1:ZAPs+OyRzeVJFGvXVDVffgCzQfjg3qU9Ig8G/MU3zZ4=
 github.com/pelletier/go-toml v1.6.0/go.mod h1:5N711Q9dKgbdkxHL+MEfF31hpT7l0S0s/t2kKREewys=
-github.com/peterbourgon/ff/v3 v3.0.0 h1:eQzEmNahuOjQXfuegsKQTSTDbf4dNvr/eNLrmJhiH7M=
-github.com/peterbourgon/ff/v3 v3.0.0/go.mod h1:UILIFjRH5a/ar8TjXYLTkIvSvekZqPm5Eb/qbGk6CT0=
+github.com/peterbourgon/ff/v3 v3.1.0 h1:5JAeDK5j/zhKFjyHEZQXwXBoDijERaos10RE+xamOsY=
+github.com/peterbourgon/ff/v3 v3.1.0/go.mod h1:XNJLY8EIl6MjMVjBS4F0+G0LYoAqs0DTa4rmHHukKDE=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 moul.io/asciimoul v1.1.0 h1:eYfYiXljSe8Z6VO84N7x8rtZE1kTLK/HmU5q9eC+T+w=