diff --git a/Dockerfile b/Dockerfile
index b48148a..7f409c2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,14 +5,14 @@ LABEL maintainer "Knut Ahlers <knut@luzifer.io>"
 ENV VAULT_VERSION 0.9.1
 ENV VAULT_HASH 6308013ee0d6278e98cdfe8d6de0162102a8d25f3bcd1e3737bf7b022a9f6702
 
-ADD https://releases.hashicorp.com/vault/${VAULT_VERSION}/vault_${VAULT_VERSION}_linux_amd64.zip /tmp/vault.zip
-
 RUN set -xe \
- && apk add --update ca-certificates \
+ && apk --no-cache add curl ca-certificates \
+ && curl -sSLfo /tmp/vault.zip https://releases.hashicorp.com/vault/${VAULT_VERSION}/vault_${VAULT_VERSION}_linux_amd64.zip \
  && echo "${VAULT_HASH}  /tmp/vault.zip" | sha256sum -c \
  && mkdir -p /opt/vault \
- && unzip /tmp/vault.zip -d /opt/vault \
+ && unzip /tmp/vault.zip -d /opt/vault && rm /tmp/vault.zip \
  && ln -sf /opt/vault/vault /usr/local/bin/vault \
+ && apk --no-cache del curl \
  && adduser -D -u 1000 vault
 
 USER vault