diff --git a/Containers/mastercontainer/start.sh b/Containers/mastercontainer/start.sh
index 986cf6e0..f4f86164 100644
--- a/Containers/mastercontainer/start.sh
+++ b/Containers/mastercontainer/start.sh
@@ -344,6 +344,7 @@ fi
 print_green "Initial startup of Nextcloud All-in-One complete!
 You should be able to open the Nextcloud AIO Interface now on port 8080 of this server!
 E.g. https://internal.ip.of.this.server:8080
+⚠️ Important: do always use an ip-address if you access this port and not a domain as HSTS might block access to it later!
 
 If your server has port 80 and 8443 open and you point a domain to your server, you can get a valid certificate automatically by opening the Nextcloud AIO Interface via:
 https://your-domain-that-points-to-this-server.tld:8443"
diff --git a/readme.md b/readme.md
index a4fb9e3f..89ae8a46 100644
--- a/readme.md
+++ b/readme.md
@@ -119,7 +119,8 @@ The following instructions are meant for installations without a web server or r
     Note: You may be interested in adjusting Nextcloud’s datadir to store the files in a different location than the default docker volume. See [this documentation](https://github.com/nextcloud/all-in-one#how-to-change-the-default-location-of-nextclouds-datadir) on how to do it.
 
 3. After the initial startup, you should be able to open the Nextcloud AIO Interface now on port 8080 of this server.<br>
-E.g. `https://ip.address.of.this.server:8080`<br><br>
+E.g. `https://ip.address.of.this.server:8080`<br>
+⚠️ **Important:** do always use an ip-address if you access this port and not a domain as HSTS might block access to it later! (It is also expected that this port uses a self-signed certificate due to security concerns which you need to accept in your browser)<br><br>
 If your firewall/router has port 80 and 8443 open/forwarded and you point a domain to your server, you can get a valid certificate automatically by opening the Nextcloud AIO Interface via:<br>
 `https://your-domain-that-points-to-this-server.tld:8443`
 4. Please do not forget to open port `3478/TCP` and `3478/UDP` in your firewall/router for the Talk container!
@@ -143,7 +144,7 @@ Only those (if you access the Mastercontainer Interface internally via port 8080
 - `3478/TCP` and `3478/UDP` for the Talk container
 
 ### Explanation of used ports:
-- `8080/TCP`: Mastercontainer Interface with self-signed certificate (works always, also if only access via IP-address is possible, e.g. `https://ip.address.of.this.server:8080/`)
+- `8080/TCP`: Mastercontainer Interface with self-signed certificate (works always, also if only access via IP-address is possible, e.g. `https://ip.address.of.this.server:8080/`) ⚠️ **Important:** do always use an ip-address if you access this port and not a domain as HSTS might block access to it later! (It is also expected that this port uses a self-signed certificate due to security concerns which you need to accept in your browser)
 - `80/TCP`: redirects to Nextcloud (is used for getting the certificate via ACME http-challenge for the Mastercontainer)
 - `8443/TCP`: Mastercontainer Interface with valid certificate (only works if port 80 and 8443 are open/forwarded in your firewall/router and you point a domain to your server. It generates a valid certificate then automatically and access via e.g. `https://public.domain.com:8443/` is possible.)
 - `443/TCP`: will be used by the Apache container later on and needs to be open/forwarded in your firewall/router
diff --git a/reverse-proxy.md b/reverse-proxy.md
index eb9c72bf..14aa18b6 100644
--- a/reverse-proxy.md
+++ b/reverse-proxy.md
@@ -699,7 +699,9 @@ Simply translate the docker run command into a docker-compose file. You can have
 Use this environment variable during the initial startup of the mastercontainer to make the apache container only listen on localhost: `--env APACHE_IP_BINDING=127.0.0.1`. **Attention:** This is only recommended to be set if you use `localhost` in your reverse proxy config to connect to your AIO instance. If you use an ip-address instead of localhost, you should set it to `0.0.0.0`.
 
 ## 4. Open the AIO interface.
-After starting AIO, you should be able to access the AIO Interface via `https://ip.address.of.the.host:8080`. Enter your domain that you've entered in the reverse proxy config and you should be done. Please do not forget to open/forward port `3478/TCP` and `3478/UDP` in your firewall/router for the Talk container!
+After starting AIO, you should be able to access the AIO Interface via `https://ip.address.of.the.host:8080`.<br>
+⚠️ **Important:** do always use an ip-address if you access this port and not a domain as HSTS might block access to it later! (It is also expected that this port uses a self-signed certificate due to security concerns which you need to accept in your browser)<br>
+Enter your domain in the AIO interface that you've used in the reverse proxy config and you should be done. Please do not forget to open/forward port `3478/TCP` and `3478/UDP` in your firewall/router for the Talk container!
 
 ## 5. Optional: get a valid certificate for the AIO interface