diff --git a/etherdump/commands/html5tidy.py b/etherdump/commands/html5tidy.py
index 0b31e57..fa02b15 100644
--- a/etherdump/commands/html5tidy.py
+++ b/etherdump/commands/html5tidy.py
@@ -43,7 +43,8 @@ def pluralize (x):
     else:
         return (x,)
 
-def html5tidy (doc, charset="utf-8", title=None, scripts=None, links=None, indent=False):
+
+def html5tidy (doc, charset="utf-8", title=None, scripts=None, links=None, indent=False, viewport_meta=None):
     if scripts:
         script_srcs = [x.attrib.get("src") for x in doc.findall(".//script")]
         for src in pluralize(scripts):
@@ -74,6 +75,14 @@ def html5tidy (doc, charset="utf-8", title=None, scripts=None, links=None, inden
         if not meta_charsets:
             meta = ET.SubElement(doc.find(".//head"), "meta", charset=charset)
 
+    # to add:
+    # <meta name="viewport" content="width=device-width,initial-scale=1">
+    # use viewport_meta="width=device-width,initial-scale=1"
+    if viewport_meta:
+        meta_viewports = [x.attrib.get("content") for x in doc.findall(".//meta") if x.attrib.get("name") == "viewport"]
+        if not meta_viewports:
+            meta = ET.SubElement(doc.find(".//head"), "meta", name="viewport", content=viewport_meta)
+
     if title != None:
         titleelt = doc.find(".//title")
         if not titleelt:
diff --git a/etherdump/commands/pull.py b/etherdump/commands/pull.py
index 31847dd..15a9b04 100644
--- a/etherdump/commands/pull.py
+++ b/etherdump/commands/pull.py
@@ -221,7 +221,7 @@ def main (args):
                     ver["url"] = quote(ver["path"])
                     # doc = html5lib.parse(html, treebuilder="etree", override_encoding="utf-8", namespaceHTMLElements=False)
                     doc = html5lib.parse(html, treebuilder="etree", namespaceHTMLElements=False)
-                    html5tidy(doc, indent=True, title=padid, scripts=args.script, links=links)
+                    html5tidy(doc, indent=True, title=padid, scripts=args.script, links=links, viewport_meta="width=device-width,initial-scale=1")
                     with open(ver["path"], "w") as f:
                         # f.write(html.encode("utf-8"))
                         print(ET.tostring(doc, method="html", encoding="unicode"), file=f)