diff --git a/CHANGELOG.md b/CHANGELOG.md
index 634c43340..e9725a3d0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,8 @@
 # v1.6.0-rc.4
 ## mm/dd/2019
 
+1. [](#improved)
+    * Renamed `Grav\Framework\File\Formatter\FormatterInterface` to `Grav\Framework\File\Interfaces\FileFormatterInterface`
 1. [](#bugfix)
     * Fixed `FlexUser` loosing ACL information
     * Fixed `FlexUser::find()` breaking when nothing is found
diff --git a/system/config/system.yaml b/system/config/system.yaml
index c07e32efe..0656fc3d0 100644
--- a/system/config/system.yaml
+++ b/system/config/system.yaml
@@ -76,7 +76,7 @@ cache:
   enabled: true                                  # Set to true to enable caching
   check:
     method: file                                 # Method to check for updates in pages: file|folder|hash|none
-  driver: auto                                   # One of: auto|file|apc|xcache|memcache|wincache
+  driver: auto                                   # One of: auto|file|apcu|memcache|wincache
   prefix: 'g'                                    # Cache prefix string (prevents cache conflicts)
   purge_at: '0 4 * * *'                          # How often to purge old file cache (using new scheduler)
   clear_at: '0 3 * * *'                           # How often to clear cache (using new scheduler)
diff --git a/system/src/Grav/Framework/Flex/Storage/AbstractFilesystemStorage.php b/system/src/Grav/Framework/Flex/Storage/AbstractFilesystemStorage.php
index d1d56d002..689694f8f 100644
--- a/system/src/Grav/Framework/Flex/Storage/AbstractFilesystemStorage.php
+++ b/system/src/Grav/Framework/Flex/Storage/AbstractFilesystemStorage.php
@@ -15,10 +15,10 @@ use Grav\Common\File\CompiledJsonFile;
 use Grav\Common\File\CompiledMarkdownFile;
 use Grav\Common\File\CompiledYamlFile;
 use Grav\Common\Grav;
-use Grav\Framework\File\Formatter\FormatterInterface;
 use Grav\Framework\File\Formatter\JsonFormatter;
 use Grav\Framework\File\Formatter\MarkdownFormatter;
 use Grav\Framework\File\Formatter\YamlFormatter;
+use Grav\Framework\File\Interfaces\FileFormatterInterface;
 use Grav\Framework\Flex\Interfaces\FlexStorageInterface;
 use RocketTheme\Toolbox\File\File;
 use RocketTheme\Toolbox\ResourceLocator\UniformResourceLocator;
@@ -30,10 +30,10 @@ use RuntimeException;
  */
 abstract class AbstractFilesystemStorage implements FlexStorageInterface
 {
-    /** @var FormatterInterface */
+    /** @var FileFormatterInterface */
     protected $dataFormatter;
 
-    protected function initDataFormatter($formatter) : void
+    protected function initDataFormatter($formatter): void
     {
         // Initialize formatter.
         if (!\is_array($formatter)) {
@@ -49,7 +49,7 @@ abstract class AbstractFilesystemStorage implements FlexStorageInterface
      * @param string $filename
      * @return null|string
      */
-    protected function detectDataFormatter(string $filename) : ?string
+    protected function detectDataFormatter(string $filename): ?string
     {
         if (preg_match('|(\.[a-z0-9]*)$|ui', $filename, $matches)) {
             switch ($matches[1]) {
@@ -69,7 +69,7 @@ abstract class AbstractFilesystemStorage implements FlexStorageInterface
      * @param string $filename
      * @return File
      */
-    protected function getFile(string $filename) : File
+    protected function getFile(string $filename): File
     {
         $filename = $this->resolvePath($filename);
 
@@ -94,7 +94,7 @@ abstract class AbstractFilesystemStorage implements FlexStorageInterface
      * @param string $path
      * @return string
      */
-    protected function resolvePath(string $path) : string
+    protected function resolvePath(string $path): string
     {
         /** @var UniformResourceLocator $locator */
         $locator = Grav::instance()['locator'];
@@ -111,7 +111,7 @@ abstract class AbstractFilesystemStorage implements FlexStorageInterface
      *
      * @return string
      */
-    protected function generateKey() : string
+    protected function generateKey(): string
     {
         return substr(hash('sha256', random_bytes(32)), 0, 32);
     }
@@ -122,7 +122,7 @@ abstract class AbstractFilesystemStorage implements FlexStorageInterface
      * @param  string $key
      * @return bool
      */
-    protected function validateKey(string $key) : bool
+    protected function validateKey(string $key): bool
     {
         return (bool) preg_match('/^[^\\/\\?\\*:;{}\\\\\\n]+$/u', $key);
     }