diff --git a/resources/templates/html.css b/resources/templates/html.css
index cbf615e524..cf04ea3f4a 100644
--- a/resources/templates/html.css
+++ b/resources/templates/html.css
@@ -303,6 +303,22 @@ ol {
   margin: 1em 0;
 }
 
+ol[type="a"] {
+    list-style-type: lower-alpha;
+}
+
+ol[type="A"] {
+    list-style-type: upper-alpha;
+}
+
+ol[type="i"] {
+    list-style-type: lower-roman;
+}
+
+ol[type="I"] {
+    list-style-type: upper-roman;
+}
+
 li {
   display: list-item;
 }
diff --git a/src/calibre/ebooks/oeb/transforms/flatcss.py b/src/calibre/ebooks/oeb/transforms/flatcss.py
index e4d3937df9..5f8443aa5e 100644
--- a/src/calibre/ebooks/oeb/transforms/flatcss.py
+++ b/src/calibre/ebooks/oeb/transforms/flatcss.py
@@ -430,6 +430,8 @@ class CSSFlattener(object):
             except (ValueError, SyntaxErr):
                 pass
             del node.attrib['bgcolor']
+        if tag == 'ol' and 'type' in node.attrib:
+            del node.attrib['type']
         if cssdict.get('font-weight', '').lower() == 'medium':
             cssdict['font-weight'] = 'normal'  # ADE chokes on font-weight medium