diff --git a/src/calibre/ebooks/docx/styles.py b/src/calibre/ebooks/docx/styles.py
index 4572eb59f2..1201f696c2 100644
--- a/src/calibre/ebooks/docx/styles.py
+++ b/src/calibre/ebooks/docx/styles.py
@@ -437,7 +437,8 @@ class Styles(object):
             '''\
             body { font-family: %s; font-size: %s; color: %s }
 
-            ul, ol, p { margin: 0; padding: 0 }
+            /* In word all paragraphs have zero margins unless explicitly specified in a style */
+            ul, ol, p, h1, h2, h3, h4, h5, h6 { margin: 0; padding: 0 }
 
             sup.noteref a { text-decoration: none }