diff --git a/question/type/ddwtos/tests/walkthrough_test.php b/question/type/ddwtos/tests/walkthrough_test.php
index 7467f7b23f2..1ac41f8fbf1 100644
--- a/question/type/ddwtos/tests/walkthrough_test.php
+++ b/question/type/ddwtos/tests/walkthrough_test.php
@@ -120,7 +120,7 @@ class qtype_ddwtos_walkthrough_test extends qbehaviour_walkthrough_test_base {
                 $this->get_contains_try_again_button_expectation(true),
                 $this->get_does_not_contain_correctness_expectation(),
                 new question_pattern_expectation('/' .
-                        preg_quote(get_string('notcomplete', 'qbehaviour_interactive')) . '/'),
+                        preg_quote(get_string('notcomplete', 'qbehaviour_interactive'), '/') . '/'),
                 $this->get_contains_hint_expectation('This is the first hint'));
 
         // Do try again.
@@ -409,7 +409,7 @@ class qtype_ddwtos_walkthrough_test extends qbehaviour_walkthrough_test_base {
                 $this->get_contains_try_again_button_expectation(true),
                 $this->get_does_not_contain_correctness_expectation(),
                 new question_pattern_expectation('/' .
-                        preg_quote(get_string('notcomplete', 'qbehaviour_interactive')) . '/'),
+                        preg_quote(get_string('notcomplete', 'qbehaviour_interactive'), '/') . '/'),
                 $this->get_contains_hint_expectation('This is the first hint'),
                 $this->get_contains_num_parts_correct(2),
                 $this->get_contains_standard_partiallycorrect_combined_feedback_expectation(),
@@ -463,7 +463,7 @@ class qtype_ddwtos_walkthrough_test extends qbehaviour_walkthrough_test_base {
                 $this->get_contains_try_again_button_expectation(true),
                 $this->get_does_not_contain_correctness_expectation(),
                 new question_pattern_expectation('/' .
-                        preg_quote(get_string('notcomplete', 'qbehaviour_interactive')) . '/'),
+                        preg_quote(get_string('notcomplete', 'qbehaviour_interactive'), '/') . '/'),
                 $this->get_contains_hint_expectation('This is the second hint'),
                 $this->get_contains_num_parts_correct(2),
                 $this->get_contains_standard_partiallycorrect_combined_feedback_expectation(),
@@ -757,6 +757,6 @@ class qtype_ddwtos_walkthrough_test extends qbehaviour_walkthrough_test_base {
                 $this->get_contains_drop_box_expectation('3', 3, true, 'correct'),
                 $this->get_contains_correct_expectation(),
                 new question_pattern_expectation('/' .
-                        preg_quote('The [quick] brown [fox] jumped over the [lazy] dog.') . '/'));
+                        preg_quote('The [quick] brown [fox] jumped over the [lazy] dog.', '/') . '/'));
     }
 }