diff --git a/clients/mod/assign/feedback/onlinejudge/locallib.php b/clients/mod/assign/feedback/onlinejudge/locallib.php
index a4aba76..bc58f1f 100644
--- a/clients/mod/assign/feedback/onlinejudge/locallib.php
+++ b/clients/mod/assign/feedback/onlinejudge/locallib.php
@@ -432,7 +432,7 @@ public function view(stdClass $grade) {
                 $i++;
             }
             if (!empty($lines)) {
-                $item = implode($lines, '<hr>');
+                $item = implode('<hr>', $lines);
             }
         }
         $item = format_text($item, FORMAT_MOODLE, array('allowid' => true)); // popup details links require id
diff --git a/clients/mod/assign/feedback/onlinejudge/source.php b/clients/mod/assign/feedback/onlinejudge/source.php
index 06618f8..4ef70c7 100644
--- a/clients/mod/assign/feedback/onlinejudge/source.php
+++ b/clients/mod/assign/feedback/onlinejudge/source.php
@@ -118,6 +118,6 @@
     $lines[] = $line;
 }
 if (!empty($lines)) {
-    $item = implode($lines, '<hr>');
+    $item = implode('<hr>', $lines);
 }
 include('source.html');
\ No newline at end of file
diff --git a/clients/mod/assign/feedback/onlinejudge/version.php b/clients/mod/assign/feedback/onlinejudge/version.php
index f1b7e67..2c57e8e 100644
--- a/clients/mod/assign/feedback/onlinejudge/version.php
+++ b/clients/mod/assign/feedback/onlinejudge/version.php
@@ -39,10 +39,10 @@
 //  This fragment is called by /admin/index.php
 ////////////////////////////////////////////////////////////////////////////////
 
-$plugin->version = 2020100400;
+$plugin->version = 2020100401;
 $plugin->requires = 2017111300;  // Requires this Moodle version
 $plugin->component = 'assignfeedback_onlinejudge';
 $plugin->maturity = MATURITY_BETA;
-$plugin->release = "v3.1-r1"; // User-friendly version number
+$plugin->release = "v3.1-r2"; // User-friendly version number
 $plugin->dependencies = array('local_onlinejudge' => 2020100700);