diff --git a/lib/dml/pgsql_native_moodle_database.php b/lib/dml/pgsql_native_moodle_database.php
index 4f82edaca7e43..9fa697f2a03d5 100644
--- a/lib/dml/pgsql_native_moodle_database.php
+++ b/lib/dml/pgsql_native_moodle_database.php
@@ -277,12 +277,12 @@ public function get_tables($usecache=true) {
             return $this->tables;
         }
         $this->tables = array();
-        $prefix = str_replace('_', '\\\\_', $this->prefix);
+        $prefix = str_replace('_', '|_', $this->prefix);
         // Get them from information_schema instead of catalog as far as
         // we want to get only own session temp objects (catalog returns all)
         $sql = "SELECT table_name
                   FROM information_schema.tables
-                 WHERE table_name LIKE '$prefix%'
+                 WHERE table_name LIKE '$prefix%' ESCAPE '|'
                    AND table_type IN ('BASE TABLE', 'LOCAL TEMPORARY')";
         $this->query_start($sql, null, SQL_QUERY_AUX);
         $result = pg_query($this->pgsql, $sql);