diff --git a/classes/local/step/directory_file_list_trait.php b/classes/local/step/directory_file_list_trait.php
index a90fb04e..ea094c4a 100644
--- a/classes/local/step/directory_file_list_trait.php
+++ b/classes/local/step/directory_file_list_trait.php
@@ -16,7 +16,6 @@
 
 namespace tool_dataflows\local\step;
 
-use MoodleQuickForm;
 use tool_dataflows\helper;
 
 /**
@@ -171,19 +170,21 @@ public function validate_for_run() {
     /**
      * Apply various constraints/transforms to the list of files
      *
-     * @param  array<string> $filelist
-     * @param  mixed         $returnvalue
-     * @param  mixed         $offset
-     * @param  mixed         $limit
+     * @param  array         $filelist
+     * @param  string        $returnvalue
+     * @param  string        $sort
+     * @param  int           $offset
+     * @param  int           $limit
      * @param  bool          $includedir
-     * @param  string        $path
+     * @param  string        $basepath
+     * @param  string        $pattern
      * @return array Will return true or an array of errors.
      */
     public function apply_list_constraints(
         array $filelist,
-        $returnvalue,
+        string $returnvalue,
         string $sort,
-        $offset,
+        int $offset,
         ?int $limit,
         bool $includedir,
         string $basepath,
diff --git a/classes/local/step/sftp_directory_file_list_trait.php b/classes/local/step/sftp_directory_file_list_trait.php
index 7edf1f88..54677d6a 100644
--- a/classes/local/step/sftp_directory_file_list_trait.php
+++ b/classes/local/step/sftp_directory_file_list_trait.php
@@ -46,7 +46,7 @@ trait sftp_directory_file_list_trait {
     public static function form_define_fields(): array {
         $fields = array_merge(
             self::sftp_form_define_fields('list'),
-            self::directory_file_list_form_define_fields(),
+            self::directory_file_list_form_define_fields()
         );
 
         return $fields;
@@ -89,7 +89,7 @@ public function run() {
             $config->limit,
             isset($config->subdirectories),
             $path,
-            $config->pattern,
+            $config->pattern
         );
 
         return $filelist;
diff --git a/classes/local/step/sftp_trait.php b/classes/local/step/sftp_trait.php
index eaad541d..fce14b9a 100644
--- a/classes/local/step/sftp_trait.php
+++ b/classes/local/step/sftp_trait.php
@@ -130,6 +130,7 @@ public function form_add_custom_inputs(\MoodleQuickForm &$mform, $behaviour = 'c
      * Validate the configuration settings.
      *
      * @param object $config
+     * @param string $behaviour
      * @return true|\lang_string[] true if valid, an array of errors otherwise
      */
     public function validate_config($config, $behaviour = 'copy') {
@@ -203,6 +204,7 @@ public function validate_config($config, $behaviour = 'copy') {
     /**
      * Perform any extra validation that is required only for runs.
      *
+     * @param string $behaviour
      * @return true|array Will return true or an array of errors.
      */
     public function validate_for_run($behaviour = 'copy') {
diff --git a/tests/tool_dataflows_sftp_test.php b/tests/tool_dataflows_sftp_test.php
index 12afef4a..04786f3a 100644
--- a/tests/tool_dataflows_sftp_test.php
+++ b/tests/tool_dataflows_sftp_test.php
@@ -30,7 +30,8 @@
  */
 class tool_dataflows_sftp_test extends \advanced_testcase {
 
-    private array $filelist = [
+    /** @var array list of realistic file paths to test. */
+    private $filelist = [
         'test.txt',
         'test.pdf',
         'test.csv',