diff --git a/Containers/mastercontainer/start.sh b/Containers/mastercontainer/start.sh
index f215f6c6..f4121c92 100644
--- a/Containers/mastercontainer/start.sh
+++ b/Containers/mastercontainer/start.sh
@@ -180,7 +180,7 @@ It is set to '$APACHE_PORT'."
     fi
 fi
 if [ -n "$APACHE_IP_BINDING" ]; then
-    if ! echo "$APACHE_IP_BINDING" | grep -q '^[0-9]\+\.[0-9]\+\.[0-9]\+\.[0-9]\+$\|^[0-9a-f:]\+$'; then
+    if ! echo "$APACHE_IP_BINDING" | grep -q '^[0-9]\+\.[0-9]\+\.[0-9]\+\.[0-9]\+$\|^[0-9a-f:]\+$\|^@INTERNAL$'; then
         print_red "You provided an ip-address for the apache container's ip-binding but it was not a valid ip-address.
 It is set to '$APACHE_IP_BINDING'."
         exit 1