diff --git a/backup/moodle2/backup_stepslib.php b/backup/moodle2/backup_stepslib.php
index 0a1f9fa4efe..d1b5d244908 100644
--- a/backup/moodle2/backup_stepslib.php
+++ b/backup/moodle2/backup_stepslib.php
@@ -319,7 +319,8 @@ class backup_module_structure_step extends backup_structure_step {
         // attach format plugin structure to $module element, only one allowed
         $this->add_plugin_structure('format', $module, false);
 
-        // attach plagiarism plugin structure to $module element, only one allowed
+        // attach plagiarism plugin structure to $module element, there can be potentially
+        // many plagiarism plugins storing information about this course
         $this->add_plugin_structure('plagiarism', $module, true);
 
         // Define the tree
@@ -421,7 +422,8 @@ class backup_course_structure_step extends backup_structure_step {
         // course reports can save course data if required
         $this->add_plugin_structure('coursereport', $course, true);
 
-        // attach plagiarism plugin structure to $course element, only one allowed
+        // attach plagiarism plugin structure to $course element, there can be potentially
+        // many plagiarism plugins storing information about this course
         $this->add_plugin_structure('plagiarism', $course, true);
 
         // Build the tree