diff --git a/docker-compose.yml b/docker-compose.yml
index d258b66..71c341a 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -58,6 +58,15 @@ services:
       # SSMTP_AUTH_METHOD:
       # SSMTP_USE_STARTTLS:
       # SSMTP_FROMLINE_OVERRIDE:
+      #
+      #
+      # The PROXY_IP environment variable lets you set the IP address
+      # (range) of the reverse proxy used for TLS termination, which forwards
+      # its requests to this container. When this reverse proxy runs on the
+      # Docker host, the default below applies. In case the reverse proxy is
+      # hosted in a separate container, this setting needs to be adjusted.
+      #
+      # PROXY_IP: 172.17.0.1/12
 
 # having the dbdata volume is required to persist our
 # data between PostgreSQL container updates; without
diff --git a/start.sh b/start.sh
index fb00e6d..92db83b 100755
--- a/start.sh
+++ b/start.sh
@@ -100,6 +100,8 @@ ${LSMB_MAIL_SMTPHOST:+smtphost=$LSMB_MAIL_SMTPHOST
 }${LSMB_MAIL_SMTPAUTHMECH:+smtpauthmech=$LSMB_MAIL_SMTPAUTHMECH
 }
 
+[proxy]
+ip=${PROXY_IP:-172.17.0.1/16}
 EOF
   export LSMB_CONFIG_FILE='/tmp/ledgersmb.conf'
 fi