diff --git a/lisp/ox-html.el b/lisp/ox-html.el
index 6c712f652..651b6fc85 100644
--- a/lisp/ox-html.el
+++ b/lisp/ox-html.el
@@ -286,9 +286,9 @@ for the JavaScript code in this tag.
             padding: 2px; font-size: 80%; font-weight: normal; }
   .timestamp { color: #bebebe; }
   .timestamp-kwd { color: #5f9ea0; }
-  .right  { margin-left: auto; margin-right: 0px;  text-align: right; }
-  .left   { margin-left: 0px;  margin-right: auto; text-align: left; }
-  .center { margin-left: auto; margin-right: auto; text-align: center; }
+  .org-right  { margin-left: auto; margin-right: 0px;  text-align: right; }
+  .org-left   { margin-left: 0px;  margin-right: auto; text-align: left; }
+  .org-center { margin-left: auto; margin-right: auto; text-align: center; }
   .underline { text-decoration: underline; }
   #postamble p, #preamble p { font-size: 90%; margin: .2em; }
   p.verse { margin-left: 3%; }
@@ -327,12 +327,12 @@ for the JavaScript code in this tag.
   caption.t-above { caption-side: top; }
   caption.t-bottom { caption-side: bottom; }
   td, th { vertical-align:top;  }
-  th.right  { text-align: center;  }
-  th.left   { text-align: center;   }
-  th.center { text-align: center; }
-  td.right  { text-align: right;  }
-  td.left   { text-align: left;   }
-  td.center { text-align: center; }
+  th.org-right  { text-align: center;  }
+  th.org-left   { text-align: center;   }
+  th.org-center { text-align: center; }
+  td.org-right  { text-align: right;  }
+  td.org-left   { text-align: left;   }
+  td.org-center { text-align: center; }
   dt { font-weight: bold; }
   .footpara:nth-child(2) { display: inline; }
   .footpara { display: block; }
@@ -3273,7 +3273,7 @@ channel."
 	  (if (not (plist-get info :html-table-align-individual-fields)) ""
 	    (format (if (and (boundp 'org-html-format-table-no-css)
 			     org-html-format-table-no-css)
-			" align=\"%s\"" " class=\"%s\"")
+			" align=\"%s\"" " class=\"org-%s\"")
 		    (org-export-table-cell-alignment table-cell info)))))
     (when (or (not contents) (string= "" (org-trim contents)))
       (setq contents " "))
@@ -3393,7 +3393,7 @@ contextual information."
 	    (alignspec
 	     (if (and (boundp 'org-html-format-table-no-css)
 		      org-html-format-table-no-css)
-		 "align=\"%s\"" "class=\"%s\""))
+		 "align=\"%s\"" "class=\"org-%s\""))
 	    (table-column-specs
 	     (function
 	      (lambda (table info)
diff --git a/testing/lisp/test-org-table.el b/testing/lisp/test-org-table.el
index a8f4ff2c2..c2883e966 100644
--- a/testing/lisp/test-org-table.el
+++ b/testing/lisp/test-org-table.el
@@ -1482,11 +1482,11 @@ See also `test-org-table/copy-field'."
 
 
 <colgroup>
-<col  class=\"left\" />
+<col  class=\"org-left\" />
 </colgroup>
 <tbody>
 <tr>
-<td class=\"left\">a</td>
+<td class=\"org-left\">a</td>
 </tr>
 </tbody>
 </table>"))