diff --git a/dir2html.py b/dir2html.py
index f9355db..ed9a736 100644
--- a/dir2html.py
+++ b/dir2html.py
@@ -34,17 +34,27 @@ def ext(fname):
 def write_dir_listing(indirname, outfname):
     lines = []
     outdirname = path.dirname(outfname)
+    try:
+        os.remove(outfname) # Avoid self-listing.
+    except FileNotFoundError:
+        pass
 
     for root, dirs, files in os.walk(indirname):
+        def file_filter(f):
+            stemName, extName = path.splitext(f)
+            if extName != ".html":
+                return False
+            if ext(stemName)[1:].lower() not in CEXTS:
+                return False
+            return True
+
+        files = list(filter(file_filter, files))
         if not files:
             continue
         files.sort()
         root = path.relpath(root, outdirname)
-        lines.append('<li class="dir">{0}:<ul>'.format(root))
+        lines.append('<li class="dir"><span class="dirname">{0}</span><ul>'.format(root))
         for file in files:
-            stemName = stem(file)
-            if ext(stemName)[1:].lower() not in CEXTS:
-                continue
             lines.append('<li class="file"><a href="{0}">{1}</a></li>'
                     .format(escape(path.join(root, file)), escape(stem(file))))
         lines.append("</ul></li>")
diff --git a/dirlisting.css b/dirlisting.css
index 20e6002..8ce6370 100644
--- a/dirlisting.css
+++ b/dirlisting.css
@@ -14,13 +14,13 @@ ul {
     list-style-type: none;
 }
 
-.dir {
+.dirname {
     font-weight: bold;
     margin-top: 2em;
 }
 
-.dir > * {
-    font-weight: normal;
+.dirname:after {
+    content: ":";
 }
 
 @media screen and (min-width: 500px), print {