diff --git a/scripts/__init_env__.php b/scripts/__init_env__.php
index 8bdedcf92a..cf28583ea3 100644
--- a/scripts/__init_env__.php
+++ b/scripts/__init_env__.php
@@ -1,7 +1,7 @@
 <?php
 
 /*
- * Copyright 2011 Facebook, Inc.
+ * Copyright 2012 Facebook, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,9 @@
  */
 
 $include_path = ini_get('include_path');
-ini_set('include_path', $include_path.':'.dirname(__FILE__).'/../../');
+ini_set(
+  'include_path',
+  $include_path.PATH_SEPARATOR.dirname(__FILE__).'/../../');
 
 require_once dirname(dirname(__FILE__)).'/conf/__init_conf__.php';
 
diff --git a/scripts/__init_script__.php b/scripts/__init_script__.php
index 1be63fd2cc..e2551149c3 100644
--- a/scripts/__init_script__.php
+++ b/scripts/__init_script__.php
@@ -20,7 +20,9 @@ error_reporting(E_ALL | E_STRICT);
 ini_set('display_errors', 1);
 
 $include_path = ini_get('include_path');
-ini_set('include_path', $include_path.':'.dirname(__FILE__).'/../../');
+ini_set(
+  'include_path',
+  $include_path.PATH_SEPARATOR.dirname(__FILE__).'/../../');
 @include_once 'libphutil/scripts/__init_script__.php';
 if (!@constant('__LIBPHUTIL__')) {
   echo "ERROR: Unable to load libphutil. Update your PHP 'include_path' to ".
@@ -34,9 +36,6 @@ phutil_load_library(dirname(__FILE__).'/../src/');
 // are not vulnerable to CSRF.
 AphrontWriteGuard::allowDangerousUnguardedWrites(true);
 
-$include_path = ini_get('include_path');
-ini_set('include_path', $include_path.':'.dirname(__FILE__).'/../../');
-
 require_once dirname(dirname(__FILE__)).'/conf/__init_conf__.php';
 
 $env = isset($_SERVER['PHABRICATOR_ENV'])
diff --git a/src/infrastructure/setup/PhabricatorSetup.php b/src/infrastructure/setup/PhabricatorSetup.php
index 02b5d0a0f4..4eba25c3f6 100644
--- a/src/infrastructure/setup/PhabricatorSetup.php
+++ b/src/infrastructure/setup/PhabricatorSetup.php
@@ -233,8 +233,8 @@ final class PhabricatorSetup {
     // unreasonable and we don't need it from Apache, so do an explicit test
     // for CLI availability.
     list($err, $stdout, $stderr) = exec_manual(
-      '%s/scripts/setup/pcntl_available.php',
-      $root);
+      'php %s',
+      "{$root}/scripts/setup/pcntl_available.php");
     if ($err) {
       self::writeFailure();
       self::write("Unable to execute scripts/setup/pcntl_available.php to ".
diff --git a/webroot/index.php b/webroot/index.php
index 866591c892..e9313beeed 100644
--- a/webroot/index.php
+++ b/webroot/index.php
@@ -198,7 +198,9 @@ function setup_aphront_basics() {
     $root = $_SERVER['PHUTIL_LIBRARY_ROOT'];
   }
 
-  ini_set('include_path', $libraries_root.':'.ini_get('include_path'));
+  ini_set(
+    'include_path',
+    $libraries_root.PATH_SEPARATOR.ini_get('include_path'));
   @include_once $root.'libphutil/src/__phutil_library_init__.php';
   if (!@constant('__LIBPHUTIL__')) {
     echo "ERROR: Unable to load libphutil. Put libphutil/ next to ".