diff --git a/.environment b/.environment
index 3e001416..c471d0f3 100644
--- a/.environment
+++ b/.environment
@@ -9,3 +9,6 @@ if [ -n "$PLATFORM_APP_DIR" -a -f "$PLATFORM_APP_DIR"/composer.json ] ; then
   bin=$(composer config bin-dir --working-dir="$PLATFORM_APP_DIR" --no-interaction 2>/dev/null)
   export PATH="${PLATFORM_APP_DIR}/${bin:-vendor/bin}:${PATH}"
 fi
+
+# Set the default site URL for drush.
+export DRUSH_OPTIONS_URI=$(echo $PLATFORM_ROUTES | base64 --decode | jq -r "to_entries | map(select(.value.upstream == \"$PLATFORM_APPLICATION_NAME\")) | sort_by(.value.primary, .key) | reverse | [.[].key] | first")
\ No newline at end of file
diff --git a/.platform.app.yaml b/.platform.app.yaml
index 7a63cc7d..aab961ab 100644
--- a/.platform.app.yaml
+++ b/.platform.app.yaml
@@ -80,7 +80,6 @@ hooks:
     # fast.
     deploy: |
         set -e
-        php ./drush/platformsh_generate_drush_yml.php
         # if drupal is installed, will call the following drush commands:
         #   - `cache-rebuild`
         #   - `updatedb`
diff --git a/drush/platformsh_generate_drush_yml.php b/drush/platformsh_generate_drush_yml.php
deleted file mode 100644
index 9dbb98c1..00000000
--- a/drush/platformsh_generate_drush_yml.php
+++ /dev/null
@@ -1,80 +0,0 @@
-<?php
-/**
- * @file
- * A script that creates the .drush/drush.yml file.
- */
-
-// This file should only be executed as a PHP-CLI script.
-if (PHP_SAPI !== 'cli') {
-  exit;
-}
-
-require_once(__DIR__ . '/../vendor/autoload.php');
-
-/**
- * Returns a site URL to use with Drush, if possible.
- *
- * @return string|NULL
- */
-function _platformsh_drush_site_url() {
-  $platformsh = new \Platformsh\ConfigReader\Config();
-
-  if (!$platformsh->inRuntime()) {
-    return;
-  }
-
-  $routes = $platformsh->getUpstreamRoutes($platformsh->applicationName);
-
-  // Sort URLs, with the primary route first, then by HTTPS before HTTP, then by length.
-  usort($routes, function (array $a, array $b) {
-    // false sorts before true, normally, so negate the comparison.
-    return
-      [!$a['primary'], strpos($a['url'], 'https://') !== 0, strlen($a['url'])]
-      <=>
-      [!$b['primary'], strpos($b['url'], 'https://') !== 0, strlen($b['url'])];
-  });
-
-  // Return the url of the first one.
-  return reset($routes)['url'] ?: NULL;
-}
-
-$appRoot = dirname(__DIR__);
-$filename = $appRoot . '/.drush/drush.yml';
-
-$siteUrl = _platformsh_drush_site_url();
-
-if (empty($siteUrl)) {
-  echo "Failed to find a site URL\n";
-
-  if (file_exists($filename)) {
-    echo "The file exists but may be invalid: $filename\n";
-  }
-
-  exit(1);
-}
-
-$siteUrlYamlEscaped = json_encode($siteUrl, JSON_UNESCAPED_SLASHES);
-$scriptPath = __FILE__;
-
-$success = file_put_contents($filename, <<<EOF
-# Drush configuration file.
-# This was automatically generated by the script:
-# $scriptPath
-
-options:
-  # Set the default site URL.
-  uri: $siteUrlYamlEscaped
-
-EOF
-);
-if (!$success) {
-  echo "Failed to write file: $filename\n";
-  exit(1);
-}
-
-if (!chmod($filename, 0600)) {
-  echo "Failed to modify file permissions: $filename\n";
-  exit(1);
-}
-
-echo "Created Drush configuration file: $filename\n";