diff --git a/lib/classes/analytics/analyser/student_enrolments.php b/lib/classes/analytics/analyser/student_enrolments.php
index d35c0a33769..27f1ed88a69 100644
--- a/lib/classes/analytics/analyser/student_enrolments.php
+++ b/lib/classes/analytics/analyser/student_enrolments.php
@@ -122,7 +122,7 @@ class student_enrolments extends \core_analytics\local\analyser\by_course {
         foreach ($enrolments as $userenrolmentid => $user) {
 
             if (empty($studentids[$user->id])) {
-                // Not a student.
+                // Not a student or an analysed one.
                 continue;
             }
 
@@ -147,6 +147,9 @@ class student_enrolments extends \core_analytics\local\analyser\by_course {
             unset($user->uetimecreated);
             unset($user->uetimemodified);
 
+            // This student has been already analysed. We analyse each student once.
+            unset($studentids[$user->id]);
+
             $samplesdata[$sampleid]['course'] = $course->get_course_data();
             $samplesdata[$sampleid]['context'] = $course->get_context();
             $samplesdata[$sampleid]['user'] = $user;