diff --git a/support/init/init-script.php b/support/init/init-script.php
index 9b67daef..ad40b8bd 100644
--- a/support/init/init-script.php
+++ b/support/init/init-script.php
@@ -56,6 +56,15 @@ function __arcanist_init_script__() {
     // inspect "args", and this option generally obscures useful debugging
     // information without any benefit in the context of Phabricator.
     'zend.exception_ignore_args' => 0,
+
+    // See T13100. We'd like the regex engine to fail, rather than segfault,
+    // if handed a pathological regular expression.
+    'pcre.backtrack_limit' => 10000,
+    'pcre.recusion_limit' => 10000,
+
+    // NOTE: Phabricator applies a similar set of startup options for Web
+    // environments in "PhabricatorStartup". Changes here may also be
+    // appropriate to apply there.
   );
 
   foreach ($config_map as $config_key => $config_value) {
@@ -106,8 +115,6 @@ function __arcanist_init_script__() {
 
   PhutilErrorHandler::initialize();
 
-  PhutilErrorHandler::initialize();
-
   // If "variables_order" excludes "E", silently repair it so that $_ENV has
   // the values we expect.
   PhutilExecutionEnvironment::repairMissingVariablesOrder();