diff --git a/webroot/index.php b/webroot/index.php
index 48c03b3917..7f22c42f2e 100644
--- a/webroot/index.php
+++ b/webroot/index.php
@@ -16,6 +16,7 @@
  * limitations under the License.
  */
 
+
 error_reporting(E_ALL | E_STRICT);
 ini_set('memory_limit', -1);
 
@@ -43,6 +44,13 @@ if (!isset($_REQUEST['__path__'])) {
     "__path__ is not set. Your rewrite rules are not configured correctly.");
 }
 
+if (get_magic_quotes_gpc()) {
+  phabricator_fatal_config_error(
+    "Your server is configured with PHP 'magic_quotes_gpc' enabled. This ".
+    "feature is 'highly discouraged' by PHP's developers and you must ".
+    "disable it to run Phabricator. Consult the PHP manual for instructions.");
+}
+
 require_once dirname(dirname(__FILE__)).'/conf/__init_conf__.php';
 
 try {