diff --git a/competency/classes/api.php b/competency/classes/api.php
index a7f8b888c79..f2cfd884cc3 100644
--- a/competency/classes/api.php
+++ b/competency/classes/api.php
@@ -1349,7 +1349,8 @@ class api {
                   JOIN {user} u
                     ON u.id = uc.userid
                  WHERE (uc.status = :waitingforreview
-                    OR (uc.status = :inreview AND uc.reviewerid = :reviewerid))";
+                    OR (uc.status = :inreview AND uc.reviewerid = :reviewerid))
+                   AND u.deleted = 0";
         $ordersql = " ORDER BY c.shortname ASC";
         $params = array(
             'inreview' => user_competency::STATUS_IN_REVIEW,
diff --git a/competency/tests/api_test.php b/competency/tests/api_test.php
index d55446bee4c..ee18025d817 100644
--- a/competency/tests/api_test.php
+++ b/competency/tests/api_test.php
@@ -4564,6 +4564,9 @@ class core_competency_api_testcase extends advanced_testcase {
     }
 
     public function test_list_user_competencies_to_review() {
+        global $CFG;
+        require_once($CFG->dirroot . '/user/lib.php');
+
         $dg = $this->getDataGenerator();
         $this->resetAfterTest();
         $ccg = $dg->get_plugin_generator('core_competency');
@@ -4580,6 +4583,7 @@ class core_competency_api_testcase extends advanced_testcase {
 
         $u1 = $dg->create_user();
         $u2 = $dg->create_user();
+        $u3 = $dg->create_user();
         $f1 = $ccg->create_framework();
         $c1 = $ccg->create_competency(['competencyframeworkid' => $f1->get_id()]);
         $c2 = $ccg->create_competency(['competencyframeworkid' => $f1->get_id()]);
@@ -4596,14 +4600,23 @@ class core_competency_api_testcase extends advanced_testcase {
             'status' => user_competency::STATUS_IDLE]);
         $uc2c = $ccg->create_user_competency(['userid' => $u2->id, 'competencyid' => $c3->get_id(),
             'status' => user_competency::STATUS_IN_REVIEW]);
+        $uc3a = $ccg->create_user_competency(['userid' => $u3->id, 'competencyid' => $c3->get_id(),
+            'status' => user_competency::STATUS_WAITING_FOR_REVIEW]);
 
         // The reviewer can review all plans waiting for review, or in review where they are the reviewer.
         $this->setUser($reviewer);
         $result = api::list_user_competencies_to_review();
-        $this->assertEquals(3, $result['count']);
+        $this->assertEquals(4, $result['count']);
         $this->assertEquals($uc2a->get_id(), $result['competencies'][0]->usercompetency->get_id());
         $this->assertEquals($uc1b->get_id(), $result['competencies'][1]->usercompetency->get_id());
         $this->assertEquals($uc1c->get_id(), $result['competencies'][2]->usercompetency->get_id());
+        $this->assertEquals($uc3a->get_id(), $result['competencies'][3]->usercompetency->get_id());
+
+        // Now, let's delete user 3.
+        // It should not be listed on user competencies to review any more.
+        user_delete_user($u3);
+        $result = api::list_user_competencies_to_review();
+        $this->assertEquals(3, $result['count']);
 
         // The reviewer cannot view the plans when they do not have the permission in the user's context.
         role_assign($roleprohibit, $reviewer->id, context_user::instance($u2->id)->id);