diff --git a/src/infrastructure/daemon/control/reference/PhabricatorDaemonReference.php b/src/infrastructure/daemon/control/reference/PhabricatorDaemonReference.php
index fc801ccccd..9bb57ba603 100644
--- a/src/infrastructure/daemon/control/reference/PhabricatorDaemonReference.php
+++ b/src/infrastructure/daemon/control/reference/PhabricatorDaemonReference.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.
@@ -63,15 +63,21 @@ final class PhabricatorDaemonReference {
       return false;
     }
 
-    // This may fail if we can't signal the process because we are running as
-    // a different user (for example, we are 'apache' and the process is some
-    // other user's, or we are a normal user and the process is root's), but
-    // we can check the error code to figure out if the process exists.
-    $is_running = posix_kill($pid, 0);
-    if (posix_get_last_error() == 1) {
-      // "Operation Not Permitted", indicates that the PID exists. If it
-      // doesn't, we'll get an error 3 ("No such process") instead.
-      $is_running = true;
+    if (function_exists('posix_kill')) {
+      // This may fail if we can't signal the process because we are running as
+      // a different user (for example, we are 'apache' and the process is some
+      // other user's, or we are a normal user and the process is root's), but
+      // we can check the error code to figure out if the process exists.
+      $is_running = posix_kill($pid, 0);
+      if (posix_get_last_error() == 1) {
+        // "Operation Not Permitted", indicates that the PID exists. If it
+        // doesn't, we'll get an error 3 ("No such process") instead.
+        $is_running = true;
+      }
+    } else {
+      // If we don't have the posix extension, just exec.
+      list($err) = exec_manual('ps %s', $pid);
+      $is_running = ($err == 0);
     }
 
     return $is_running;
diff --git a/src/infrastructure/daemon/control/reference/__init__.php b/src/infrastructure/daemon/control/reference/__init__.php
index 66e65b55fe..f9db1b4a69 100644
--- a/src/infrastructure/daemon/control/reference/__init__.php
+++ b/src/infrastructure/daemon/control/reference/__init__.php
@@ -6,6 +6,7 @@
 
 
 
+phutil_require_module('phutil', 'future/exec');
 phutil_require_module('phutil', 'utils');