diff --git a/classes/external/score_get_course_scores.php b/classes/external/score_get_course_scores.php
index 42d8483..f13fad6 100644
--- a/classes/external/score_get_course_scores.php
+++ b/classes/external/score_get_course_scores.php
@@ -8,12 +8,11 @@
 use core_external\external_value;
 use invalid_parameter_exception;
 use local_adler\adler_score_helpers;
+use local_adler\moodle_core;
 use moodle_exception;
 use restricted_context_exception;
 
 class score_get_course_scores extends external_api {
-    private static string $context_course = context_course::class;
-
     public static function execute_parameters(): external_function_parameters {
         return new external_function_parameters(
             array(
@@ -37,7 +36,7 @@ public static function execute($course_id): array {
         $course_id = $params['course_id'];
 
         // Permission check
-        $context = static::$context_course::instance($course_id);
+        $context = di::get(moodle_core::class)->context_course_instance($course_id);
         static::validate_context($context);
 
         // get cmids of all modules in course
diff --git a/tests/external/score_get_course_scores_test.php b/tests/external/score_get_course_scores_test.php
index b2b5abb..7aedf07 100644
--- a/tests/external/score_get_course_scores_test.php
+++ b/tests/external/score_get_course_scores_test.php
@@ -7,6 +7,7 @@
 use core\di;
 use local_adler\adler_score_helpers;
 use local_adler\lib\adler_externallib_testcase;
+use local_adler\moodle_core;
 use Mockery;
 use moodle_database;
 use ReflectionClass;
@@ -38,12 +39,8 @@ public function test_execute($element_count) {
 
         // mock context
         $context_mock = Mockery::mock(context_module::class);
-        $context_mock->shouldReceive('instance')->andReturn($context_mock);
-
-        $reflected_class = new ReflectionClass(score_get_course_scores::class);
-        $property = $reflected_class->getProperty('context_course');
-        $property->setAccessible(true);
-        $property->setValue(null, $context_mock->mockery_getName());
+        $moodle_core_mock = Mockery::mock(moodle_core::class);
+        $moodle_core_mock->shouldReceive('context_course_instance')->andReturn($context_mock);
 
         // mock validate_context
         $score_get_course_scores_mock = Mockery::mock(score_get_course_scores::class)->makePartial();