diff --git a/question/question.php b/question/question.php
index 0f78fc79109..a37d4199337 100644
--- a/question/question.php
+++ b/question/question.php
@@ -178,6 +178,7 @@ if ($id) {
     if ($makecopy) {
         // If we are duplicating a question, add some indication to the question name.
         $question->name = get_string('questionnamecopy', 'question', $question->name);
+        $question->idnumber = null;
         $question->beingcopied = true;
     }
 
diff --git a/question/tests/behat/copy_questions.feature b/question/tests/behat/copy_questions.feature
index 7ae37082c6b..e6e60967137 100644
--- a/question/tests/behat/copy_questions.feature
+++ b/question/tests/behat/copy_questions.feature
@@ -18,8 +18,8 @@ Feature: A teacher can duplicate questions in the question bank
       | contextlevel | reference | name           |
       | Course       | C1        | Test questions |
     And the following "questions" exist:
-      | questioncategory | qtype | name                       | questiontext                  |
-      | Test questions   | essay | Test question to be copied | Write about whatever you want |
+      | questioncategory | qtype | name                       | questiontext                  | idnumber |
+      | Test questions   | essay | Test question to be copied | Write about whatever you want | qid      |
     And I log in as "teacher1"
     And I am on "Course 1" course homepage
     And I navigate to "Question bank > Questions" in current page administration