diff --git a/flextype/Flextype.php b/flextype/Flextype.php
index 5a407095..f64fb5a6 100755
--- a/flextype/Flextype.php
+++ b/flextype/Flextype.php
@@ -66,7 +66,7 @@ class Flextype
         Registry::set('site', []);
 
         // Set site items if site config exists
-        if (Filesystem::fileExists($site_config = CONFIG_PATH . '/' . 'site.yml')) {
+        if (Filesystem::fileExists($site_config = CONFIG_PATH . '/' . 'site.yaml')) {
             Registry::set('site', Yaml::parseFile($site_config));
         } else {
             throw new \RuntimeException("Flextype site config file does not exist.");
diff --git a/flextype/Plugins.php b/flextype/Plugins.php
index 5f43b96f..70fec038 100755
--- a/flextype/Plugins.php
+++ b/flextype/Plugins.php
@@ -99,7 +99,7 @@ class Plugins
 
             // Go through...
             foreach ($plugins_list as $plugin) {
-                if (Filesystem::fileExists($_plugin = PLUGINS_PATH . '/' . $plugin . '/' . $plugin . '.yml')) {
+                if (Filesystem::fileExists($_plugin = PLUGINS_PATH . '/' . $plugin . '/' . $plugin . '.yaml')) {
                     $plugins_cache_id .= filemtime($_plugin);
                 }
             }
@@ -119,11 +119,11 @@ class Plugins
                 // Go through...
                 foreach ($plugins_list as $plugin) {
 
-                    if (Filesystem::fileExists($_plugin_manifest = PLUGINS_PATH . '/' . $plugin . '/' . $plugin . '.yml')) {
+                    if (Filesystem::fileExists($_plugin_manifest = PLUGINS_PATH . '/' . $plugin . '/' . $plugin . '.yaml')) {
                         $plugin_manifest = Yaml::parseFile($_plugin_manifest);
                     }
 
-                    $_plugins_config[basename($_plugin_manifest, '.yml')] = $plugin_manifest;
+                    $_plugins_config[basename($_plugin_manifest, '.yaml')] = $plugin_manifest;
                 }
 
                 Registry::set('plugins', $_plugins_config);
@@ -135,7 +135,7 @@ class Plugins
         if (is_array($plugins_list) && count($plugins_list) > 0) {
             foreach (static::$locales as $locale => $locale_title) {
                 foreach ($plugins_list as $plugin) {
-                    $language_file = PLUGINS_PATH . '/' . $plugin . '/languages/' . $locale . '.yml';
+                    $language_file = PLUGINS_PATH . '/' . $plugin . '/languages/' . $locale . '.yaml';
                     if (Filesystem::fileExists($language_file)) {
                         I18n::add($plugin, $locale, Yaml::parseFile($language_file));
                     }
diff --git a/flextype/Themes.php b/flextype/Themes.php
index 4e864722..457cc320 100644
--- a/flextype/Themes.php
+++ b/flextype/Themes.php
@@ -60,7 +60,7 @@ class Themes
         if (Cache::driver()->contains($theme_cache_id)) {
             Registry::set('themes.'.Registry::get('site.theme'), Cache::driver()->fetch($theme_cache_id));
         } else {
-            if (Filesystem::fileExists($theme_manifest_file = THEMES_PATH . '/' . $theme . '/' . $theme . '.yml')) {
+            if (Filesystem::fileExists($theme_manifest_file = THEMES_PATH . '/' . $theme . '/' . $theme . '.yaml')) {
                 $theme_manifest = Yaml::parseFile($theme_manifest_file);
                 Registry::set('themes.'.Registry::get('site.theme'), $theme_manifest);
                 Cache::driver()->save($theme_cache_id, $theme_manifest);