diff --git a/src/calibre/ebooks/mobi/mobiml.py b/src/calibre/ebooks/mobi/mobiml.py
index 11df25f18d..4ceec726f7 100644
--- a/src/calibre/ebooks/mobi/mobiml.py
+++ b/src/calibre/ebooks/mobi/mobiml.py
@@ -468,7 +468,8 @@ class MobiMLizer(object):
                                     pass
                                 istate.attrib['height'] = str(int(height))
                         item.unload_data_from_memory()
-        elif tag == 'hr' and asfloat(style['width']) > 0:
+        elif tag == 'hr' and asfloat(style['width']) > 0 and style._get('width') not in {'100%', 'auto'}:
+            rawti = style._get('text-indent')
             prop = style['width'] / self.profile.width
             istate.attrib['width'] = "%d%%" % int(round(prop * 100))
         elif display == 'table':