diff --git a/modules/markup/html.go b/modules/markup/html.go
index a7d66cc249..2ea0b56f72 100644
--- a/modules/markup/html.go
+++ b/modules/markup/html.go
@@ -327,7 +327,7 @@ func (ctx *postProcessCtx) postProcess(rawHTML []byte) ([]byte, error) {
_, _ = res.WriteString("<html><body>")
// Strip out nuls - they're always invalid
- _, _ = nulCleaner.WriteString(res, string(tagCleaner.ReplaceAll(rawHTML, []byte("<$1"))))
+ _, _ = res.Write(tagCleaner.ReplaceAll([]byte(nulCleaner.Replace(string(rawHTML))), []byte("<$1")))
// close the tags
_, _ = res.WriteString("</body></html>")