diff --git a/lang/en_utf8/quiz.php b/lang/en_utf8/quiz.php
index 365120897fc..d0469f111af 100644
--- a/lang/en_utf8/quiz.php
+++ b/lang/en_utf8/quiz.php
@@ -252,6 +252,7 @@ $string['incorrect'] = 'Incorrect';
 $string['indivresp'] = 'Responses of Individuals to Each Item';
 $string['info'] = 'Info';
 $string['introduction'] = 'Introduction';
+$string['invalidcategory'] = 'Category ID is invalid';
 $string['invalidnumericanswer'] = 'One of the answers you entered was not a valid number.';
 $string['invalidnumerictolerance'] = 'One of the tolerances you entered was not a valid number.';
 $string['invalidsource'] = 'The source is not accepted as valid.';
diff --git a/question/export.php b/question/export.php
index fe8401032a9..6c0d19ae981 100644
--- a/question/export.php
+++ b/question/export.php
@@ -68,7 +68,7 @@
     if (!empty($categoryid)) {
         $validcats = question_category_options( $course->id, true, false );
         if (!array_key_exists( $categoryid, $validcats)) {
-            print_error( "Category id ($categoryid) is not permitted." );
+            print_error( 'invalidcategory','quiz' );
         }
     }