diff --git a/Dockerfile b/Dockerfile
index 0ed410b..e1ed919 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,9 @@
-FROM alpine:3.11
+FROM alpine:3.17
 MAINTAINER Andrey Arapov <andrey.arapov@nixaid.com>
 
 RUN apk update && \
     apk upgrade && \
-    apk add dovecot dovecot-lmtpd runit socklog ca-certificates && \
+    apk add dovecot dovecot-lmtpd dovecot-pigeonhole-plugin runit socklog ca-certificates && \
     rm -rf /etc/service
 
 COPY service /etc/service/