diff --git a/engine.go b/engine.go
index e97273a..4258657 100644
--- a/engine.go
+++ b/engine.go
@@ -40,7 +40,7 @@ func (e *Engine) RegisterBlock(name string, td Renderer) {
 //
 // Examples:
 //
-// * https://github.com/osteele/liquid/blob/master/filters/filters.go
+// * https://github.com/osteele/liquid/blob/main/filters/standard_filters.go
 //
 // * https://github.com/osteele/gojekyll/blob/master/filters/filters.go
 func (e *Engine) RegisterFilter(name string, fn interface{}) {