diff --git a/classes/text_filter.php b/classes/text_filter.php
index cee4f56..69ed3b9 100644
--- a/classes/text_filter.php
+++ b/classes/text_filter.php
@@ -14,6 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <https://www.gnu.org/licenses/>.
 
+namespace filter_filtercodes;
+
 defined('MOODLE_INTERNAL') || die;
 
 /**