diff --git a/boost.module b/boost.module
index 61ac034adc8cc5eefcbaafa0bb32e42640c8cb39..8ebf7e35fc69a1d4a3ab280c960f6d29e2cfc691 100644
--- a/boost.module
+++ b/boost.module
@@ -95,7 +95,7 @@ function boost_menu($may_cache) {
  */
 function boost_init() {
   // Stop right here unless we're being called for an ordinary page request
-  if (strpos($_SERVER['PHP_SELF'], 'index.php') === FALSE)
+  if (strpos($_SERVER['SCRIPT_FILENAME'], 'index.php') === FALSE)
     return;
 
   // TODO: check interaction with other modules that use ob_start(); this