diff --git a/src/calibre/gui2/tweak_book/editor/smart/html.py b/src/calibre/gui2/tweak_book/editor/smart/html.py
index 43319521de..973d513441 100644
--- a/src/calibre/gui2/tweak_book/editor/smart/html.py
+++ b/src/calibre/gui2/tweak_book/editor/smart/html.py
@@ -15,6 +15,7 @@ from PyQt4.Qt import QTextEdit
 from calibre import prepare_string_for_xml
 from calibre.gui2 import error_dialog
 from calibre.gui2.tweak_book.editor.syntax.html import ATTR_NAME, ATTR_END, ATTR_START, ATTR_VALUE
+from calibre.utils.icu import utf16_length
 
 get_offset = itemgetter(0)
 PARAGRAPH_SEPARATOR = '\u2029'
@@ -216,8 +217,14 @@ class HTMLSmarts(NullSmarts):
         def add_tag(tag):
             a = QTextEdit.ExtraSelection()
             a.cursor, a.format = editor.textCursor(), editor.match_paren_format
-            a.cursor.setPosition(tag.start_block.position() + tag.start_offset)
-            a.cursor.setPosition(tag.end_block.position() + tag.end_offset + 1, a.cursor.KeepAnchor)
+            a.cursor.setPosition(tag.start_block.position()), a.cursor.movePosition(a.cursor.EndOfBlock, a.cursor.KeepAnchor)
+            text = unicode(a.cursor.selectedText())
+            start_pos = utf16_length(text[:tag.start_offset])
+            a.cursor.setPosition(tag.end_block.position()), a.cursor.movePosition(a.cursor.EndOfBlock, a.cursor.KeepAnchor)
+            text = unicode(a.cursor.selectedText())
+            end_pos = utf16_length(text[:tag.end_offset + 1])
+            a.cursor.setPosition(tag.start_block.position() + start_pos)
+            a.cursor.setPosition(tag.end_block.position() + end_pos, a.cursor.KeepAnchor)
             ans.append(a)
 
         c = editor.textCursor()