diff --git a/includes/bootstrap.inc b/includes/bootstrap.inc
index 9f37dfc..8cbcfc6 100644
--- a/includes/bootstrap.inc
+++ b/includes/bootstrap.inc
@@ -838,6 +838,14 @@ function drupal_get_filename($type, $name, $filename = NULL) {
   // drupal_static().
   static $files = array(), $dirs = array();
 
+  // We use drupal static for the bad records so we can test it.
+  // Drupal static fast pattern is used as this function may be called often.
+  static $drupal_static_fast;
+  if (!isset($drupal_static_fast)) {
+    $drupal_static_fast['bad'] = &drupal_static(__FUNCTION__ . ':bad');
+  }
+  $bad = &$drupal_static_fast['bad'];
+
   // Profiles are a special case: they have a fixed location and naming.
   if ($type == 'profile') {
     $profile_filename = "profiles/$name/$name.profile";
@@ -887,7 +895,18 @@ function drupal_get_filename($type, $name, $filename = NULL) {
         $extension = $type;
       }
 
-      if (!isset($dirs[$dir][$extension])) {
+      // See if we have a cached list of files missing from the file system.
+      if (is_null($bad)) {
+        $cache = cache_get('drupal_get_filename:bad');
+        if (!empty($cache->data)) {
+          $bad = $cache->data;
+        }
+        else {
+          $bad = array();
+        }
+      }
+
+      if (!isset($dirs[$dir][$extension]) && !isset($bad[$type][$name])) {
         $dirs[$dir][$extension] = TRUE;
         if (!function_exists('drupal_system_listing')) {
           require_once DRUPAL_ROOT . '/includes/common.inc';
@@ -907,6 +926,16 @@ function drupal_get_filename($type, $name, $filename = NULL) {
   if (isset($files[$type][$name])) {
     return $files[$type][$name];
   }
+  elseif (!isset($bad[$type][$name])) {
+    // Add the missing file to a temporary cache and throw a watchdog alert.
+    $bad[$type][$name] = TRUE;
+    cache_set('drupal_get_filename:bad', $bad, 'cache', CACHE_TEMPORARY);
+
+    // We don't have the watchdog table in the tests.
+    if (db_table_exists('watchdog')) {
+      watchdog('system', 'The following @type is missing from the file system: @name.', array('@type' => $type, '@name' => $name), WATCHDOG_ALERT);
+    }
+  }
 }
 
 /**
diff --git a/modules/simpletest/tests/bootstrap.test b/modules/simpletest/tests/bootstrap.test
index f723c63..016ff12 100644
--- a/modules/simpletest/tests/bootstrap.test
+++ b/modules/simpletest/tests/bootstrap.test
@@ -379,6 +379,18 @@ class BootstrapGetFilenameTestCase extends DrupalUnitTestCase {
     // automatically check there for 'script' files, just as it does for (e.g.)
     // 'module' files in modules.
     $this->assertIdentical(drupal_get_filename('script', 'test'), 'scripts/test.script', t('Retrieve test script location.'));
+
+    // Generate a non-existing module name.
+    $non_existing_module = uniqid("", TRUE);
+
+    // Searching for an item that does not exist returns NULL.
+    $this->assertNull(drupal_get_filename('module', $non_existing_module), 'Searching for an item that does not exist returns NULL.');
+
+    // Get the bad records static from drupal_get_filename.
+    $bad = &drupal_static('drupal_get_filename:bad');
+
+    // Searching for an item that does not exist creates a static record in drupal_get_filename.
+    $this->assertTrue($bad['module'][$non_existing_module], 'Searching for an item that does not exist creates a static record in drupal_get_filename.');
   }
 }