diff --git includes/bootstrap.inc includes/bootstrap.inc
index 1c13c6f..c311bea 100644
--- includes/bootstrap.inc
+++ includes/bootstrap.inc
@@ -675,9 +675,12 @@ function drupal_get_filename($type, $name, $filename = NULL) {
   // when a database connection fails.
   else {
     try {
-      if (function_exists('db_query')) {
-        $file = db_query("SELECT filename FROM {system} WHERE name = :name AND type = :type", array(':name' => $name, ':type' => $type))->fetchField();
-        if (file_exists(DRUPAL_ROOT . '/' . $file)) {
+      if (class_exists('Database') && Database::isActiveConnection()) {
+        // If the 'profile' type is given, it's actually stored as 'module', so
+        // query using that type.
+        $type_token = $type == 'profile' ? 'module' : $type;
+        $file = db_query("SELECT filename FROM {system} WHERE name = :name AND type = :type", array(':name' => $name, ':type' => $type_token))->fetchField();
+        if ($file && file_exists(DRUPAL_ROOT . '/' . $file)) {
           $files[$type][$name] = $file;
         }
       }
diff --git modules/simpletest/tests/bootstrap.test modules/simpletest/tests/bootstrap.test
index 333f34b..5fa7b2a 100644
--- modules/simpletest/tests/bootstrap.test
+++ modules/simpletest/tests/bootstrap.test
@@ -322,26 +322,53 @@ class HookBootExitTestCase extends DrupalWebTestCase {
 }
 
 /**
- * Test drupal_get_filename()'s availability.
+ * Test drupal_get_filename()'s availability without a DB.
  */
-class BootstrapGetFilenameTestCase extends DrupalUnitTestCase {
+class BootstrapGetFilenameTestCaseNoDatabase extends DrupalUnitTestCase {
 
   public static function getInfo() {
     return array(
-      'name' => 'Get filename test',
-      'description' => 'Test that drupal_get_filename() works correctly when the file is not found in the database.',
+      'name' => 'Get filename test (no database)',
+      'description' => 'Test that drupal_get_filename() works correctly without an active database connection.',
       'group' => 'Bootstrap',
     );
   }
 
   /**
-   * Test that drupal_get_filename() works correctly when the file is not found in the database.
+   * Test that drupal_get_filename() works correctly when not using the DB.
    */
   function testDrupalGetFilename() {
-    // Reset the static cache so we can test the "db is not active" code of
-    // drupal_get_filename().
-    drupal_static_reset('drupal_get_filename');
+    // Retrieving the location of a module.
+    $this->assertIdentical(drupal_get_filename('module', 'php'), 'modules/php/php.module', t('Retrieve module location.'));
+
+    // Retrieving the location of a theme.
+    $this->assertIdentical(drupal_get_filename('theme', 'stark'), 'themes/stark/stark.info', t('Retrieve theme location.'));
+
+    // Retrieving the location of a theme engine.
+    $this->assertIdentical(drupal_get_filename('theme_engine', 'phptemplate'), 'themes/engines/phptemplate/phptemplate.engine', t('Retrieve theme engine location.'));
+
+    // Retrieving the location of an install profile.
+    $this->assertIdentical(drupal_get_filename('profile', 'standard'), 'profiles/standard/standard.profile', t('Retrieve install profile location.'));
+  }
+}
+
+/**
+ * Test drupal_get_filename()'s availability with a DB.
+ */
+class BootstrapGetFilenameTestCaseDatabase extends DrupalWebTestCase {
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Get filename test (database)',
+      'description' => 'Test that drupal_get_filename() works correctly with an active database connection.',
+      'group' => 'Bootstrap',
+    );
+  }
 
+  /**
+   * Test that drupal_get_filename() works correctly when the file is not found in the database.
+   */
+  function testDrupalGetFilename() {
     // Retrieving the location of a module.
     $this->assertIdentical(drupal_get_filename('module', 'php'), 'modules/php/php.module', t('Retrieve module location.'));
 
@@ -351,8 +378,11 @@ class BootstrapGetFilenameTestCase extends DrupalUnitTestCase {
     // Retrieving the location of a theme engine.
     $this->assertIdentical(drupal_get_filename('theme_engine', 'phptemplate'), 'themes/engines/phptemplate/phptemplate.engine', t('Retrieve theme engine location.'));
 
-    // Retrieving a file that is definitely not stored in the database.
+    // Retrieving the location of an install profile.
     $this->assertIdentical(drupal_get_filename('profile', 'standard'), 'profiles/standard/standard.profile', t('Retrieve install profile location.'));
+
+    // Retrieving the location of an install profile, that isn't in the DB.
+    $this->assertIdentical(drupal_get_filename('profile', 'testing'), 'profiles/testing/testing.profile', t('Retrieve install profile location, without DB.'));
   }
 }
 
@@ -497,4 +527,3 @@ class BootstrapOverrideServerVariablesTestCase extends DrupalUnitTestCase {
     }
   }
 }
-