diff --git a/course/externallib.php b/course/externallib.php
index 1d91b94313f..88c0693048e 100644
--- a/course/externallib.php
+++ b/course/externallib.php
@@ -1254,7 +1254,6 @@ class core_course_external extends external_api {
             $newcategory = new stdClass();
             $newcategory->name = $category['name'];
             $newcategory->parent = $category['parent'];
-            $newcategory->sortorder = 999; // Same as in the course/editcategory.php .
             // Format the description.
             if (!empty($category['description'])) {
                 $newcategory->description = $category['description'];
diff --git a/course/tests/externallib_test.php b/course/tests/externallib_test.php
index 1eb755ed70f..dac68374803 100644
--- a/course/tests/externallib_test.php
+++ b/course/tests/externallib_test.php
@@ -111,8 +111,12 @@ class core_course_external_testcase extends externallib_advanced_testcase {
         $category2 = $DB->get_record('course_categories', array('id' => $category2->id));
         $category3 = $DB->get_record('course_categories', array('id' => $category3->id));
 
-        $this->assertGreaterThanOrEqual($category1->sortorder, $category3->sortorder);
-        $this->assertGreaterThanOrEqual($category2->sortorder, $category3->sortorder);
+        // sortorder sequence (and sortorder) must be:
+        // category 1
+        //   category 3
+        // category 2
+        $this->assertGreaterThan($category1->sortorder, $category3->sortorder);
+        $this->assertGreaterThan($category3->sortorder, $category2->sortorder);
 
         // Call without required capability
         $this->unassignUserCapability('moodle/category:manage', $contextid, $roleid);