diff --git a/course/externallib.php b/course/externallib.php
index 4d8c7e8cc70..3e806227d19 100644
--- a/course/externallib.php
+++ b/course/externallib.php
@@ -217,6 +217,7 @@ class core_course_external extends external_api {
                                     'id' => new external_value(PARAM_INT, 'activity id'),
                                     'url' => new external_value(PARAM_URL, 'activity url', VALUE_OPTIONAL),
                                     'name' => new external_value(PARAM_RAW, 'activity module name'),
+                                    'instance' => new external_value(PARAM_INT, 'instance id', VALUE_OPTIONAL),
                                     'description' => new external_value(PARAM_RAW, 'activity description', VALUE_OPTIONAL),
                                     'visible' => new external_value(PARAM_INT, 'is the module visible', VALUE_OPTIONAL),
                                     'modicon' => new external_value(PARAM_URL, 'activity icon url'),
diff --git a/course/tests/externallib_test.php b/course/tests/externallib_test.php
index a4e423450ba..a0c29f497e5 100644
--- a/course/tests/externallib_test.php
+++ b/course/tests/externallib_test.php
@@ -611,12 +611,14 @@ class core_course_externallib_testcase extends externallib_advanced_testcase {
                 $formattedtext = format_text($cm->content, FORMAT_HTML,
                     array('noclean' => true, 'para' => false, 'filter' => false));
                 $this->assertEquals($formattedtext, $module['description']);
+                $this->assertEquals($forumcm->instance, $module['instance']);
                 $testexecuted = $testexecuted + 1;
             } else if ($module['id'] == $labelcm->id and $module['modname'] == 'label') {
                 $cm = $modinfo->cms[$labelcm->id];
                 $formattedtext = format_text($cm->content, FORMAT_HTML,
                     array('noclean' => true, 'para' => false, 'filter' => false));
                 $this->assertEquals($formattedtext, $module['description']);
+                $this->assertEquals($labelcm->instance, $module['instance']);
                 $testexecuted = $testexecuted + 1;
             }
         }