diff --git a/Makefile b/Makefile
index d9d69143..63a0c6e8 100644
--- a/Makefile
+++ b/Makefile
@@ -15,16 +15,12 @@ protocol:
 index.html: README.rst
 	$(eval TITLE := $(shell echo '$(basename $<)' | sed -E 's|zip-0{0,3}|ZIP |'): $(shell grep -E '^(\.\.)?\s*Title:' $< |sed -E 's|.*Title:\s*||'))
 	rst2html5 -v --title="$(TITLE)" $< >$@
-	sed -i.sedbak 's|</head>|<meta name="viewport" content="width=device-width, initial-scale=1"><link rel="stylesheet" href="css/style.css"></head>|' $@
-	sed -i.sedbak 's|<a href="\([^":]*\).rst">|<a href="\1">|' $@
-	rm -f *.sedbak
+	./edithtml.sh $@
 
 %.html: %.rst
 	$(eval TITLE := $(shell echo '$(basename $<)' | sed -E 's|zip-0{0,3}|ZIP |'): $(shell grep -E '^(\.\.)?\s*Title:' $< |sed -E 's|.*Title:\s*||'))
 	rst2html5 -v --title="$(TITLE)" $< >$@
-	sed -i.sedbak 's|</head>|<meta name="viewport" content="width=device-width, initial-scale=1"><link rel="stylesheet" href="css/style.css"></head>|' $@
-	sed -i.sedbak 's|<a href="\([^":]*\).rst">|<a href="\1">|' $@
-	rm -f *.sedbak
+	./edithtml.sh $@
 
 README.rst: makeindex.sh README.template $(filter-out README.rst,$(wildcard *.rst))
 	./makeindex.sh | cat README.template - >README.rst
diff --git a/edithtml.sh b/edithtml.sh
new file mode 100755
index 00000000..cdb1472a
--- /dev/null
+++ b/edithtml.sh
@@ -0,0 +1,5 @@
+#!/bin/sh
+
+sed -i.sedbak 's|</head>|<meta name="viewport" content="width=device-width, initial-scale=1"><link rel="stylesheet" href="css/style.css"></head>|' $@
+sed -i.sedbak 's|<a href="\([^":]*\).rst">|<a href="\1">|' $@
+rm -f *.sedbak