diff --git a/src/applications/config/check/PhabricatorElasticsearchSetupCheck.php b/src/applications/config/check/PhabricatorElasticsearchSetupCheck.php
index 157db5e141..cd29ecdc78 100644
--- a/src/applications/config/check/PhabricatorElasticsearchSetupCheck.php
+++ b/src/applications/config/check/PhabricatorElasticsearchSetupCheck.php
@@ -1,82 +1,88 @@
 <?php
 
 final class PhabricatorElasticsearchSetupCheck extends PhabricatorSetupCheck {
 
   public function getDefaultGroup() {
     return self::GROUP_OTHER;
   }
 
   protected function executeChecks() {
+    // TODO: Avoid fataling if we don't have a master database configured
+    // but have the MySQL search index configured. See T12965.
+    if (PhabricatorEnv::isReadOnly()) {
+      return;
+    }
+
     $services = PhabricatorSearchService::getAllServices();
 
     foreach ($services as $service) {
       try {
         $host = $service->getAnyHostForRole('read');
       } catch (PhabricatorClusterNoHostForRoleException $e) {
         // ignore the error
         continue;
       }
       if ($host instanceof PhabricatorElasticsearchHost) {
         $index_exists = null;
         $index_sane = null;
         try {
           $engine = $host->getEngine();
           $index_exists = $engine->indexExists();
           if ($index_exists) {
             $index_sane = $engine->indexIsSane();
           }
         } catch (Exception $ex) {
           $summary = pht('Elasticsearch is not reachable as configured.');
           $message = pht(
             'Elasticsearch is configured (with the %s setting) but Phabricator'.
             ' encountered an exception when trying to test the index.'.
             "\n\n".
             '%s',
             phutil_tag('tt', array(), 'cluster.search'),
             phutil_tag('pre', array(), $ex->getMessage()));
 
           $this->newIssue('elastic.misconfigured')
             ->setName(pht('Elasticsearch Misconfigured'))
             ->setSummary($summary)
             ->setMessage($message)
             ->addRelatedPhabricatorConfig('cluster.search');
           return;
         }
 
         if (!$index_exists) {
           $summary = pht(
             'You enabled Elasticsearch but the index does not exist.');
 
           $message = pht(
             'You likely enabled cluster.search without creating the '.
             'index. Use the following command to create a new index.');
 
           $this
             ->newIssue('elastic.missing-index')
             ->setName(pht('Elasticsearch Index Not Found'))
             ->addCommand('./bin/search init')
             ->setSummary($summary)
             ->setMessage($message);
 
         } else if (!$index_sane) {
           $summary = pht(
             'Elasticsearch index exists but needs correction.');
 
           $message = pht(
             'Either the Phabricator schema for Elasticsearch has changed '.
             'or Elasticsearch created the index automatically. '.
             'Use the following command to rebuild the index.');
 
           $this
             ->newIssue('elastic.broken-index')
             ->setName(pht('Elasticsearch Index Schema Mismatch'))
             ->addCommand('./bin/search init')
             ->setSummary($summary)
             ->setMessage($message);
         }
       }
     }
   }
 
 
 }