diff --git a/README.md b/README.md
index ea93811..5c5d056 100644
--- a/README.md
+++ b/README.md
@@ -177,6 +177,8 @@ any environment variables prefixed with `FOURGET_` will be added to the generate
 
 the entrypoint will automatically set the `CAPTCHA_DATASET` value for you based on directory names and number of files in each
 
+to set `INSTANCES` pass a comma separated string of urls (FOURGET_INSTANCES = "https://4get.ca,https://domain.tld")
+
 
 ```
 version: "3.7"
diff --git a/docker/gen_config.php b/docker/gen_config.php
index b7e036e..dff39cb 100644
--- a/docker/gen_config.php
+++ b/docker/gen_config.php
@@ -25,6 +25,9 @@ function type_to_string($n) {
                 return $n ? 'true' : 'false';
         }
         if ($type === "string") {
+                if(is_numeric($n)) {
+                        return $n;
+                }
                 return "\"$n\"";
         }
         if ($type === "array") {
@@ -49,7 +52,7 @@ function detect_captcha_dirs() {
 }
 
 
-$special_keys = ["CAPTCHA_DATASET"];
+$special_keys = ["CAPTCHA_DATASET", "INSTANCES"];
 
 $output = "<?php\n // This file was generated by docker/gen_config.php\n";
 
@@ -61,8 +64,11 @@ continue;
         }
 
 
-if($key === "CAPTCHA_DATASET") {
-        $output = $output . "\tconst " . $key . " = " . type_to_string(detect_captcha_dirs()) . ";\n";
+        if($key === "CAPTCHA_DATASET") {
+                $output = $output . "\tconst " . $key . " = " . type_to_string(detect_captcha_dirs()) . ";\n";
+        }
+        if($key === "INSTANCES") {
+                $output = $output . "\tconst " . $key . " = " . type_to_string(explode(',', $val)) . ";\n";
         }
 
 }