diff --git a/ext/comment/main.php b/ext/comment/main.php
index a3baf0c5..8751fb39 100644
--- a/ext/comment/main.php
+++ b/ext/comment/main.php
@@ -357,7 +357,7 @@ class CommentList extends SimpleExtension {
 	 *
 	 * FIXME: assumes comments are posted via HTTP...
 	 */
-	public function get_hash() {
+	public static function get_hash() {
 		return md5($_SERVER['REMOTE_ADDR'] . date("%Y%m%d"));
 	}