diff --git a/.gitattributes b/.gitattributes
index 26a33c44a..ab3adfc3c 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -6,7 +6,5 @@
 /.github_changelog_generator export-ignore
 /.php_cs.dist export-ignore
 /.scrutinizer.yml export-ignore
-/.styleci.yml export-ignore
-/.travis.yml export-ignore
 /.phpstan.neon.dist export-ignore
 /.phpunit.xml.dist export-ignore
diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
index 704ec8c92..67cd3500f 100644
--- a/.github/workflows/phpstan.yml
+++ b/.github/workflows/phpstan.yml
@@ -3,6 +3,9 @@ name: PHPStan
 on:
   pull_request:
   push:
+    branches:
+      - 1.x
+      - 2.x
 
 jobs:
   phpstan:
diff --git a/.phpstan/baseline.neon b/.phpstan/baseline.neon
index 876a6c3e1..c1ba43ad2 100644
--- a/.phpstan/baseline.neon
+++ b/.phpstan/baseline.neon
@@ -1,6 +1,6 @@
 parameters:
     ignoreErrors:
-        - message: '#^Access to undefined constant Liip\\ImagineBundle\\Config\\Filter\\Type\\FilterAbstract::NAME\.$#'
+        - message: '#^Access to undefined constant static\(Liip\\ImagineBundle\\Config\\Filter\\Type\\FilterAbstract\)::NAME\.$#'
           paths:
               - ../Config/Filter/Type/FilterAbstract.php
         - message: '#^Unsafe usage of new static\(\)\.$#'
diff --git a/.phpstan/stubs/AdapterInterface.stub b/.phpstan/stubs/AdapterInterface.stub
new file mode 100644
index 000000000..567fc5a29
--- /dev/null
+++ b/.phpstan/stubs/AdapterInterface.stub
@@ -0,0 +1,118 @@
+<?php
+
+namespace League\Flysystem;
+
+interface AdapterInterface extends ReadInterface
+{
+    /**
+     * @const  VISIBILITY_PUBLIC  public visibility
+     */
+    const VISIBILITY_PUBLIC = 'public';
+
+    /**
+     * @const  VISIBILITY_PRIVATE  private visibility
+     */
+    const VISIBILITY_PRIVATE = 'private';
+
+    /**
+     * Write a new file.
+     *
+     * @param string $path
+     * @param string $contents
+     * @param Config $config   Config object
+     *
+     * @return array|false false on failure file meta data on success
+     */
+    public function write($path, $contents, Config $config);
+
+    /**
+     * Write a new file using a stream.
+     *
+     * @param string   $path
+     * @param resource $resource
+     * @param Config   $config   Config object
+     *
+     * @return array|false false on failure file meta data on success
+     */
+    public function writeStream($path, $resource, Config $config);
+
+    /**
+     * Update a file.
+     *
+     * @param string $path
+     * @param string $contents
+     * @param Config $config   Config object
+     *
+     * @return array|false false on failure file meta data on success
+     */
+    public function update($path, $contents, Config $config);
+
+    /**
+     * Update a file using a stream.
+     *
+     * @param string   $path
+     * @param resource $resource
+     * @param Config   $config   Config object
+     *
+     * @return array|false false on failure file meta data on success
+     */
+    public function updateStream($path, $resource, Config $config);
+
+    /**
+     * Rename a file.
+     *
+     * @param string $path
+     * @param string $newpath
+     *
+     * @return bool
+     */
+    public function rename($path, $newpath);
+
+    /**
+     * Copy a file.
+     *
+     * @param string $path
+     * @param string $newpath
+     *
+     * @return bool
+     */
+    public function copy($path, $newpath);
+
+    /**
+     * Delete a file.
+     *
+     * @param string $path
+     *
+     * @return bool
+     */
+    public function delete($path);
+
+    /**
+     * Delete a directory.
+     *
+     * @param string $dirname
+     *
+     * @return bool
+     */
+    public function deleteDir($dirname);
+
+    /**
+     * Create a directory.
+     *
+     * @param string $dirname directory name
+     * @param Config $config
+     *
+     * @return array|false
+     */
+    public function createDir($dirname, Config $config);
+
+    /**
+     * Set the visibility for a file.
+     *
+     * @param string $path
+     * @param string $visibility
+     *
+     * @return array|false file meta data
+     */
+    public function setVisibility($path, $visibility);
+}
diff --git a/.phpstan/stubs/FilesystemInterface.stub b/.phpstan/stubs/FilesystemInterface.stub
new file mode 100644
index 000000000..a6b99ba06
--- /dev/null
+++ b/.phpstan/stubs/FilesystemInterface.stub
@@ -0,0 +1,284 @@
+<?php
+
+namespace League\Flysystem;
+
+use InvalidArgumentException;
+
+interface FilesystemInterface
+{
+    /**
+     * Check whether a file exists.
+     *
+     * @param string $path
+     *
+     * @return bool
+     */
+    public function has($path);
+
+    /**
+     * Read a file.
+     *
+     * @param string $path The path to the file.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return string|false The file contents or false on failure.
+     */
+    public function read($path);
+
+    /**
+     * Retrieves a read-stream for a path.
+     *
+     * @param string $path The path to the file.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return resource|false The path resource or false on failure.
+     */
+    public function readStream($path);
+
+    /**
+     * List contents of a directory.
+     *
+     * @param string $directory The directory to list.
+     * @param bool   $recursive Whether to list recursively.
+     *
+     * @return array A list of file metadata.
+     */
+    public function listContents($directory = '', $recursive = false);
+
+    /**
+     * Get a file's metadata.
+     *
+     * @param string $path The path to the file.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return array|false The file metadata or false on failure.
+     */
+    public function getMetadata($path);
+
+    /**
+     * Get a file's size.
+     *
+     * @param string $path The path to the file.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return int|false The file size or false on failure.
+     */
+    public function getSize($path);
+
+    /**
+     * Get a file's mime-type.
+     *
+     * @param string $path The path to the file.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return string|false The file mime-type or false on failure.
+     */
+    public function getMimetype($path);
+
+    /**
+     * Get a file's timestamp.
+     *
+     * @param string $path The path to the file.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return int|false The timestamp or false on failure.
+     */
+    public function getTimestamp($path);
+
+    /**
+     * Get a file's visibility.
+     *
+     * @param string $path The path to the file.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return string|false The visibility (public|private) or false on failure.
+     */
+    public function getVisibility($path);
+
+    /**
+     * Write a new file.
+     *
+     * @param string $path     The path of the new file.
+     * @param string $contents The file contents.
+     * @param array  $config   An optional configuration array.
+     *
+     * @throws FileExistsException
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function write($path, $contents, array $config = []);
+
+    /**
+     * Write a new file using a stream.
+     *
+     * @param string   $path     The path of the new file.
+     * @param resource $resource The file handle.
+     * @param array    $config   An optional configuration array.
+     *
+     * @throws InvalidArgumentException If $resource is not a file handle.
+     * @throws FileExistsException
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function writeStream($path, $resource, array $config = []);
+
+    /**
+     * Update an existing file.
+     *
+     * @param string $path     The path of the existing file.
+     * @param string $contents The file contents.
+     * @param array  $config   An optional configuration array.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function update($path, $contents, array $config = []);
+
+    /**
+     * Update an existing file using a stream.
+     *
+     * @param string   $path     The path of the existing file.
+     * @param resource $resource The file handle.
+     * @param array    $config   An optional configuration array.
+     *
+     * @throws InvalidArgumentException If $resource is not a file handle.
+     * @throws FileNotFoundException
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function updateStream($path, $resource, array $config = []);
+
+    /**
+     * Rename a file.
+     *
+     * @param string $path    Path to the existing file.
+     * @param string $newpath The new path of the file.
+     *
+     * @throws FileExistsException   Thrown if $newpath exists.
+     * @throws FileNotFoundException Thrown if $path does not exist.
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function rename($path, $newpath);
+
+    /**
+     * Copy a file.
+     *
+     * @param string $path    Path to the existing file.
+     * @param string $newpath The new path of the file.
+     *
+     * @throws FileExistsException   Thrown if $newpath exists.
+     * @throws FileNotFoundException Thrown if $path does not exist.
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function copy($path, $newpath);
+
+    /**
+     * Delete a file.
+     *
+     * @param string $path
+     *
+     * @throws FileNotFoundException
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function delete($path);
+
+    /**
+     * Delete a directory.
+     *
+     * @param string $dirname
+     *
+     * @throws RootViolationException Thrown if $dirname is empty.
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function deleteDir($dirname);
+
+    /**
+     * Create a directory.
+     *
+     * @param string $dirname The name of the new directory.
+     * @param array  $config  An optional configuration array.
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function createDir($dirname, array $config = []);
+
+    /**
+     * Set the visibility for a file.
+     *
+     * @param string $path       The path to the file.
+     * @param string $visibility One of 'public' or 'private'.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function setVisibility($path, $visibility);
+
+    /**
+     * Create a file or update if exists.
+     *
+     * @param string $path     The path to the file.
+     * @param string $contents The file contents.
+     * @param array  $config   An optional configuration array.
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function put($path, $contents, array $config = []);
+
+    /**
+     * Create a file or update if exists.
+     *
+     * @param string   $path     The path to the file.
+     * @param resource $resource The file handle.
+     * @param array    $config   An optional configuration array.
+     *
+     * @throws InvalidArgumentException Thrown if $resource is not a resource.
+     *
+     * @return bool True on success, false on failure.
+     */
+    public function putStream($path, $resource, array $config = []);
+
+    /**
+     * Read and delete a file.
+     *
+     * @param string $path The path to the file.
+     *
+     * @throws FileNotFoundException
+     *
+     * @return string|false The file contents, or false on failure.
+     */
+    public function readAndDelete($path);
+
+    /**
+     * Get a file/directory handler.
+     *
+     * @deprecated
+     *
+     * @param string  $path    The path to the file.
+     * @param Handler $handler An optional existing handler to populate.
+     *
+     * @return Handler Either a file or directory handler.
+     */
+    public function get($path, Handler $handler = null);
+
+    /**
+     * Register a plugin.
+     *
+     * @param PluginInterface $plugin The plugin to register.
+     *
+     * @return $this
+     */
+    public function addPlugin(PluginInterface $plugin);
+}
diff --git a/.phpstan/stubs/ReadInterface.stub b/.phpstan/stubs/ReadInterface.stub
new file mode 100644
index 000000000..898a8d5c8
--- /dev/null
+++ b/.phpstan/stubs/ReadInterface.stub
@@ -0,0 +1,88 @@
+<?php
+
+namespace League\Flysystem;
+
+interface ReadInterface
+{
+    /**
+     * Check whether a file exists.
+     *
+     * @param string $path
+     *
+     * @return array|bool|null
+     */
+    public function has($path);
+
+    /**
+     * Read a file.
+     *
+     * @param string $path
+     *
+     * @return array|false
+     */
+    public function read($path);
+
+    /**
+     * Read a file as a stream.
+     *
+     * @param string $path
+     *
+     * @return array|false
+     */
+    public function readStream($path);
+
+    /**
+     * List contents of a directory.
+     *
+     * @param string $directory
+     * @param bool   $recursive
+     *
+     * @return array
+     */
+    public function listContents($directory = '', $recursive = false);
+
+    /**
+     * Get all the meta data of a file or directory.
+     *
+     * @param string $path
+     *
+     * @return array|false
+     */
+    public function getMetadata($path);
+
+    /**
+     * Get the size of a file.
+     *
+     * @param string $path
+     *
+     * @return array|false
+     */
+    public function getSize($path);
+
+    /**
+     * Get the mimetype of a file.
+     *
+     * @param string $path
+     *
+     * @return array|false
+     */
+    public function getMimetype($path);
+
+    /**
+     * Get the last modified time of a file as a timestamp.
+     *
+     * @param string $path
+     *
+     * @return array|false
+     */
+    public function getTimestamp($path);
+
+    /**
+     * Get the visibility of a file.
+     *
+     * @param string $path
+     *
+     * @return array|false
+     */
+    public function getVisibility($path);
+}
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index ac9e8d527..69588e26c 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -22,6 +22,9 @@ parameters:
         - Utility
         - LiipImagineBundle.php
     scanFiles:
+        - .phpstan/stubs/AdapterInterface.stub
         - .phpstan/stubs/Event.stub
         - .phpstan/stubs/ExtensionGuesserInterface.stub
+        - .phpstan/stubs/FilesystemInterface.stub
         - .phpstan/stubs/MimeTypeGuesserInterface.stub
+        - .phpstan/stubs/ReadInterface.stub