diff --git a/Dockerfile b/Dockerfile
index 7129a21..a54322c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,7 @@ MAINTAINER Andrey Arapov <andrey.arapov@nixaid.com>
 
 RUN apk update && \
     apk upgrade && \
-    apk add dovecot runit socklog && \
+    apk add dovecot runit socklog ca-certificates && \
     rm -rf /etc/service
 
 COPY service /etc/service/