diff --git a/modules/markup/html.go b/modules/markup/html.go
index c2e574e3b29..b462b6b34b6 100644
--- a/modules/markup/html.go
+++ b/modules/markup/html.go
@@ -312,7 +312,7 @@ func (ctx *postProcessCtx) postProcess(rawHTML []byte) ([]byte, error) {
_, _ = res.WriteString("")
// 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("")