diff --git a/lisp/ox-html.el b/lisp/ox-html.el
index 476ffbec2..45984b9c4 100644
--- a/lisp/ox-html.el
+++ b/lisp/ox-html.el
@@ -2305,7 +2305,7 @@ contextual information."
   "Transcode a CENTER-BLOCK element from Org to HTML.
 CONTENTS holds the contents of the block.  INFO is a plist
 holding contextual information."
-  (format "<div class=\"center\">\n%s</div>" contents))
+  (format "<div class=\"org-center\">\n%s</div>" contents))
 
 ;;;; Clock