diff --git a/Dockerfile b/Dockerfile
index c348e52..eba179b 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -5,14 +5,17 @@ WORKDIR /go/src/github.com/Luzifer/promcertcheck
 
 RUN set -ex \
  && apk add --update git \
- && go install -ldflags "-X main.version=$(git describe --tags || git rev-parse --short HEAD || echo dev)"
+ && go install \
+      -ldflags "-X main.version=$(git describe --tags --always || echo dev)" \
+      -mod=readonly
 
 FROM alpine:latest
 
 LABEL maintainer "Knut Ahlers <knut@ahlers.me>"
 
 RUN set -ex \
- && apk --no-cache add ca-certificates
+ && apk --no-cache add \
+      ca-certificates
 
 COPY --from=builder /go/bin/promcertcheck /usr/local/bin/promcertcheck