diff --git a/dta.zip b/dta.zip
index 83d1e2867578df0141d3c8e191b5f951a10eaed8..94d05da2f2938ef029de29d6dc3a695b6d41c26e 100644
Binary files a/dta.zip and b/dta.zip differ
diff --git a/dta/classes/backend.php b/dta/classes/backend.php
index b2904ae2d946a5363e6bf42556a2e440561b72bd..892859bfb579adc78d83789783112df752258aa8 100644
--- a/dta/classes/backend.php
+++ b/dta/classes/backend.php
@@ -21,6 +21,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @copyright Gero Lueckemeyer and student project teams
  */
+namespace assignsubmission_dta\util
 
 /**
  * backend webservice contact utility class
diff --git a/dta/classes/database.php b/dta/classes/database.php
index 6f5c82a94f5545911657831ebbadbe1ca5f0ece0..28917e90a2637e42866ba607fc0e01b0ea9edc4f 100644
--- a/dta/classes/database.php
+++ b/dta/classes/database.php
@@ -14,6 +14,15 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+/**
+ * persistence layer utility class
+ *
+ * @package assignsubmission_dta
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @copyright Gero Lueckemeyer and student project teams
+ */
+namespace assignsubmission_dta\util
+
 /**
  * persistence layer utility class
  *
diff --git a/dta/classes/view.php b/dta/classes/view.php
index b5d1dc8bd8e0ded138bff08ebc3b57a24a1d7f4b..0c01db2661b04f5fff97c34bb429719750fb7203 100644
--- a/dta/classes/view.php
+++ b/dta/classes/view.php
@@ -14,6 +14,15 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
+/**
+ * utility class for DTA submission plugin result display
+ *
+ * @package assignsubmission_dta
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @copyright Gero Lueckemeyer and student project teams
+ */
+namespace assignsubmission_dta\util
+
 /**
  * utility class for DTA submission plugin result display
  *
diff --git a/dta/locallib.php b/dta/locallib.php
index 3aaadac7263cc7e23607169d7147b66634e674d9..911dc3e415eedabb3a0a8e53b3403f7542722ceb 100644
--- a/dta/locallib.php
+++ b/dta/locallib.php
@@ -18,9 +18,13 @@ defined('MOODLE_INTERNAL') || die();
 
 // Import various entity and application logic files.
 require_once($CFG->dirroot . '/mod/assign/submission/dta/models/DtaResult.php');
-require_once($CFG->dirroot . '/mod/assign/submission/dta/utils/database.php');
-require_once($CFG->dirroot . '/mod/assign/submission/dta/utils/backend.php');
-require_once($CFG->dirroot . '/mod/assign/submission/dta/utils/view.php');
+require_once($CFG->dirroot . '/mod/assign/submission/dta/classes/database.php');
+require_once($CFG->dirroot . '/mod/assign/submission/dta/classes/backend.php');
+require_once($CFG->dirroot . '/mod/assign/submission/dta/classes/view.php');
+
+use assignsubmission_dta\util\DtaBackendUtils;
+use assignsubmission_dta\util\DbUtils;
+use assignsubmission_dta\util\view_submission_utils;
 
 /**
  * library class for DTA submission plugin extending assign submission plugin base class
@@ -174,7 +178,7 @@ class assign_submission_dta extends assign_submission_plugin {
      * @param int $userid current user
      * @return bool form elements added
      */
-    public function get_form_elements_for_user($submissionorgrade, MoodleQuickForm $mform, stdClass $data, $userid): bool {
+    public function get_form_elements_for_user($submissionorgrade, MoodleQuickForm $mform, stdClass $data, int $userid): bool {
         // Prepare submission filearea.
         $data = file_prepare_standard_filemanager(
             $data,
@@ -228,7 +232,7 @@ class assign_submission_dta extends assign_submission_plugin {
      * @param string $areaid filearea id to count
      * @return int
      */
-    private function count_files($submissionid, $areaid) {
+    private function count_files(int $submissionid, string $areaid) {
         $fs = get_file_storage();
         $files = $fs->get_area_files($this->assignment->get_context()->id,
             self::COMPONENT_NAME,
diff --git a/dta/version.php b/dta/version.php
index cf9e0b3dfc3fbb1fcf5e945d95cf29f4e9e2e8d6..c1d02a029ae402daa95c32134420f8bf95e881a3 100644
--- a/dta/version.php
+++ b/dta/version.php
@@ -25,7 +25,7 @@
 defined('MOODLE_INTERNAL') || die();
 
 $plugin->version   = 3000000;
-$plugin->requires  = 2020061525; // Moodle 3.9 LTS
+$plugin->requires  = 2020061525; // Moodle 3.9 LTS. Will likely run with unsupported older versions of the 3.x branch.
 $plugin->component = 'assignsubmission_dta';
 $plugin->maturity  = MATURITY_STABLE;
 $plugin->release   = "3.0.0";