diff --git a/Containers/mastercontainer/start.sh b/Containers/mastercontainer/start.sh
index 7dc94809..cbf79d75 100644
--- a/Containers/mastercontainer/start.sh
+++ b/Containers/mastercontainer/start.sh
@@ -200,6 +200,11 @@ It needs to be a string with letters, numbers, hyphens and underscores.
 It is set to '$APACHE_ADDITIONAL_NETWORK'."
         exit 1
     fi
+    tmp_out=$(sudo -u www-data docker network connect $APACHE_ADDITIONAL_NETWORK nextcloud-aio-mastercontainer 2>&1)
+    if [ -n "$tmp_out" ] && [[ ! "$tmp_out" =~ "nextcloud-aio-mastercontainer already exists in network $APACHE_ADDITIONAL_NETWORK" ]]; then
+        print_red "Unable to connect to $APACHE_ADDITIONAL_NETWORK. Cannot continue. Error: \n $tmp_out"
+        exit 1
+    fi
 fi
 if [ -n "$TALK_PORT" ]; then
     if ! check_if_number "$TALK_PORT"; then