diff --git a/netdisco-postgresql/Dockerfile b/netdisco-postgresql/Dockerfile
index ac89687..6c55009 100644
--- a/netdisco-postgresql/Dockerfile
+++ b/netdisco-postgresql/Dockerfile
@@ -1,5 +1,5 @@
 # vim: ft=Dockerfile
-FROM docker.io/postgres:13.4-alpine
+FROM docker.io/postgres:17.2-alpine
 
 ARG BUILD_DATE
 ARG COMMITTISH=HEAD
@@ -18,12 +18,14 @@ LABEL org.label-schema.docker.schema-version="1.0" \
       org.netdisco.version=${COMMITTISH}
 
 RUN apk add --no-cache \
+  su-exec \
   curl \
   tzdata \
   tar
 
 COPY netdisco-initdb.sh /docker-entrypoint-initdb.d/
 COPY netdisco-db-entrypoint.sh netdisco-updatedb.sh /usr/local/bin/
+COPY README_UPGRADE.md /
 RUN chmod +x /usr/local/bin/netdisco-*
 
 WORKDIR /var/lib/postgresql/netdisco-sql
diff --git a/netdisco-postgresql/README_UPGRADE.md b/netdisco-postgresql/README_UPGRADE.md
new file mode 100644
index 0000000..543b762
--- /dev/null
+++ b/netdisco-postgresql/README_UPGRADE.md
@@ -0,0 +1,47 @@
+
+Beginning from version 2.09000 netdisco-docker includes Postgres 17, 
+while the existing database is an older major version.
+
+It's possible to upgrade the old database in-place using pgautoupgrade, 
+executed in the directory where docker-compose.yml is located. Make 
+sure all other netdisco containers are stopped.
+
+```
+docker run --rm -it \
+  --mount type=bind,source=$PWD/netdisco/pgdata,target=/var/lib/postgresql/data \
+  -e PGAUTO_ONESHOT=yes \
+  pgautoupgrade/pgautoupgrade:17-alpine
+```
+
+Before doing so, please make sure to have a working backup. If you don't
+have one already, a simple way to create one is:
+
+```
+docker-compose exec -u postgres netdisco-postgresql \
+    pg_dump -c -d netdisco -C --format=p > $HOME/netdisco-backup.sql
+
+```
+
+For the above command to work, or to avoid upgrading right now, edit
+docker-compose.yml to use the last version of the images that used
+Postgres 13:
+
+```
+    image: netdisco/netdisco:2.080003-postgresql
+    image: netdisco/netdisco:2.080003-backend
+    image: netdisco/netdisco:2.080003-web
+    image: netdisco/netdisco:2.080003-do
+```
+
+When you are ready to use Postgres 17, set the version numbers in image:
+to `latest` again.
+
+```
+    image: netdisco/netdisco:latest-postgresql
+    etc...
+```
+
+We apologize for the inconvenience. While we can not offer full
+Postgres DBA support or any responsibility for data loss, we try to
+help with reported issues on github or the IRC channel. 
+
diff --git a/netdisco-postgresql/netdisco-db-entrypoint.sh b/netdisco-postgresql/netdisco-db-entrypoint.sh
index e680b0b..80937e7 100644
--- a/netdisco-postgresql/netdisco-db-entrypoint.sh
+++ b/netdisco-postgresql/netdisco-db-entrypoint.sh
@@ -10,6 +10,11 @@ if [ ! -s "${PGDATA}/PG_VERSION" ]; then
     /usr/local/bin/docker-entrypoint.sh "$@"
 fi
 
+if ! grep -q "17" "${PGDATA}/PG_VERSION" ; then
+  cat /README_UPGRADE.md
+  exit 1
+fi
+
 if [ "$1" = 'postgres' ]; then
   echo >&2 -e "${COL}netdisco-db-entrypoint: starting pg privately to container${NC}"
   "${su[@]}" pg_ctl -D "$PGDATA" -o "-c listen_addresses='localhost' -c log_min_error_statement=LOG -c log_min_messages=LOG" -w start