diff --git a/src/calibre/ebooks/html_entities.py b/src/calibre/ebooks/html_entities.py
index b01494e91f..04cb3bc263 100644
--- a/src/calibre/ebooks/html_entities.py
+++ b/src/calibre/ebooks/html_entities.py
@@ -93,7 +93,7 @@ html5_entities = {
     'DifferentialD': 'ⅆ',
     'Dopf': '𝔻',
     'Dot': '¨',
-    'DotDot': '⃜',
+    'DotDot': '⃜\u20dc',
     'DotEqual': '≐',
     'DoubleContourIntegral': '∯',
     'DoubleDot': '¨',