diff --git a/Dockerfile b/Dockerfile
index ef05f826..1202c9bb 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -28,9 +28,10 @@ ENV SASLAUTHD_MECH_OPTIONS=""
 SHELL ["/bin/bash", "-o", "pipefail", "-c"]
 
 # Packages
-# hadolint ignore=DL3015
+# hadolint ignore=DL3015,DL3005
 RUN \
   apt-get update -q --fix-missing && \
+  apt-get -y upgrade && \
   apt-get -y install postfix && \
   apt-get -y install --no-install-recommends \
     altermime \