diff --git a/competency/lib.php b/competency/lib.php
index 2c61be46557..849d8d84593 100644
--- a/competency/lib.php
+++ b/competency/lib.php
@@ -133,6 +133,7 @@ function core_competency_comment_add($comment, $params) {
         $message->contexturlname = $urlname;
 
         $userpicture = new \user_picture($user);
+        $userpicture->size = 1; // Use f1 size.
         // Message each recipient.
         foreach ($recipients as $recipient) {
             $msgcopy = clone($message);
@@ -208,6 +209,7 @@ function core_competency_comment_add($comment, $params) {
         $message->contexturlname = $urlname;
 
         $userpicture = new \user_picture($user);
+        $userpicture->size = 1; // Use f1 size.
         // Message each recipient.
         foreach ($recipients as $recipient) {
             $msgcopy = clone($message);
diff --git a/competency/tests/lib_test.php b/competency/tests/lib_test.php
index dcfe80e99a3..0575f350f04 100644
--- a/competency/tests/lib_test.php
+++ b/competency/tests/lib_test.php
@@ -101,6 +101,7 @@ class core_competency_lib_testcase extends advanced_testcase {
         $this->assertObjectHasAttribute('notificationiconurl', $customdata);
         $this->assertContains('tokenpluginfile.php', $customdata->notificationiconurl);
         $userpicture = new \user_picture($u1);
+        $userpicture->size = 1; // Use f1 size.
         $userpicture->includetoken = $u2->id;
         $this->assertEquals($userpicture->get_url($PAGE)->out(false), $customdata->notificationiconurl);
 
diff --git a/message/classes/api.php b/message/classes/api.php
index 30f0d87fd6b..3f70e5318ae 100644
--- a/message/classes/api.php
+++ b/message/classes/api.php
@@ -2676,6 +2676,7 @@ class api {
         $message->smallmessage = '';
         $message->contexturl = $url->out(false);
         $userpicture = new \user_picture($userfrom);
+        $userpicture->size = 1; // Use f1 size.
         $userpicture->includetoken = $userto->id; // Generate an out-of-session token for the user receiving the message.
         $message->customdata = [
             'notificationiconurl' => $userpicture->get_url($PAGE)->out(false),
diff --git a/message/lib.php b/message/lib.php
index 83dd501551d..b850e7fe7d8 100644
--- a/message/lib.php
+++ b/message/lib.php
@@ -353,6 +353,7 @@ function message_post_message($userfrom, $userto, $message, $format) {
     $eventdata->notification    = 0;
     // User image.
     $userpicture = new user_picture($userfrom);
+    $userpicture->size = 1; // Use f1 size.
     $userpicture->includetoken = $userto->id; // Generate an out-of-session token for the user receiving the message.
     $eventdata->customdata = [
         'notificationiconurl' => $userpicture->get_url($PAGE)->out(false),
diff --git a/mod/assign/locallib.php b/mod/assign/locallib.php
index fa4cdc2d2e4..b5944a384ae 100644
--- a/mod/assign/locallib.php
+++ b/mod/assign/locallib.php
@@ -6335,6 +6335,7 @@ class assign {
         // Check if the userfrom is real and visible.
         if (!empty($userfrom->id) && core_user::is_real_user($userfrom->id)) {
             $userpicture = new user_picture($userfrom);
+            $userpicture->size = 1; // Use f1 size.
             $userpicture->includetoken = $userto->id; // Generate an out-of-session token for the user receiving the message.
             $customdata['notificationiconurl'] = $userpicture->get_url($PAGE)->out(false);
         }
diff --git a/mod/assign/tests/locallib_test.php b/mod/assign/tests/locallib_test.php
index 29bd4b5a406..af371e1841e 100644
--- a/mod/assign/tests/locallib_test.php
+++ b/mod/assign/tests/locallib_test.php
@@ -1526,6 +1526,7 @@ class mod_assign_locallib_testcase extends advanced_testcase {
         $this->assertEquals($assign->get_instance()->id, $customdata->instance);
         $this->assertEquals('feedbackavailable', $customdata->messagetype);
         $userpicture = new user_picture($teacher);
+        $userpicture->size = 1; // Use f1 size.
         $this->assertEquals($userpicture->get_url($PAGE)->out(false), $customdata->notificationiconurl);
         $this->assertEquals(0, $customdata->uniqueidforuser);   // Not used in this case.
         $this->assertFalse($customdata->blindmarking);
diff --git a/mod/feedback/lib.php b/mod/feedback/lib.php
index 124bc3c9ebc..89ea0ef204e 100644
--- a/mod/feedback/lib.php
+++ b/mod/feedback/lib.php
@@ -2639,6 +2639,7 @@ function feedback_send_email($cm, $feedback, $course, $user, $completed = null)
                 $eventdata->contexturlname   = $info->feedback;
                 // User image.
                 $userpicture = new user_picture($user);
+                $userpicture->size = 1; // Use f1 size.
                 $userpicture->includetoken = $teacher->id; // Generate an out-of-session token for the user receiving the message.
                 $customdata['notificationiconurl'] = $userpicture->get_url($PAGE)->out(false);
                 $eventdata->customdata = $customdata;
diff --git a/mod/forum/classes/task/send_user_notifications.php b/mod/forum/classes/task/send_user_notifications.php
index 7b22ba0ea6c..d177f6e8a32 100644
--- a/mod/forum/classes/task/send_user_notifications.php
+++ b/mod/forum/classes/task/send_user_notifications.php
@@ -353,6 +353,7 @@ class send_user_notifications extends \core\task\adhoc_task {
         $eventdata->contexturlname = $discussion->name;
         // User image.
         $userpicture = new \user_picture($author);
+        $userpicture->size = 1; // Use f1 size.
         $userpicture->includetoken = $this->recipient->id; // Generate an out-of-session token for the user receiving the message.
         $eventdata->customdata = [
             'cmid' => $cm->id,
diff --git a/mod/lesson/essay.php b/mod/lesson/essay.php
index b7903a6bfdb..f295735606f 100644
--- a/mod/lesson/essay.php
+++ b/mod/lesson/essay.php
@@ -225,6 +225,7 @@ switch ($mode) {
         }
 
         $userpicture = new user_picture($USER);
+        $userpicture->size = 1; // Use f1 size.
         foreach ($attempts as $attempt) {
             $essayinfo = lesson_page_type_essay::extract_useranswer($attempt->useranswer);
             if ($essayinfo->graded && !$essayinfo->sent) {
diff --git a/mod/quiz/locallib.php b/mod/quiz/locallib.php
index 12b54ecb9b1..90f8987f051 100644
--- a/mod/quiz/locallib.php
+++ b/mod/quiz/locallib.php
@@ -1588,6 +1588,7 @@ function quiz_send_notification($recipient, $submitter, $a) {
     $eventdata->contexturl        = $a->quizreviewurl;
     $eventdata->contexturlname    = $a->quizname;
     $userpicture = new user_picture($submitter);
+    $userpicture->size = 1; // Use f1 size.
     $userpicture->includetoken = $recipient->id; // Generate an out-of-session token for the user receiving the message.
     $eventdata->customdata        = [
         'cmid' => $a->quizcmid,