diff --git a/mod/chat/gui_ajax/theme/bubble/chat.css b/mod/chat/gui_ajax/theme/bubble/chat.css
index c6f3b8c620d..59a57af7255 100644
--- a/mod/chat/gui_ajax/theme/bubble/chat.css
+++ b/mod/chat/gui_ajax/theme/bubble/chat.css
@@ -13,6 +13,8 @@
 #input-message {background:#FFFFFF url(input.png) repeat-x scroll 0 0;padding:0 9px;border: 1px solid #999;border-radius: 9px;-moz-border-radius: 9px;}
 .mdl-chat-entry,
 .mdl-chat-my-entry {clear:both;}
+.dir-rtl .mdl-chat-entry,
+.dir-rtl .mdl-chat-my-entry {height: 90px;}
 
 .mdl-chat-entry .chat-event {padding-bottom:15px;}
 
@@ -20,6 +22,8 @@
 .chat-message .picture {vertical-align:middle;}
 .chat-message .right {text-align:right;}
 .chat-message .left {text-align:left;}
+.dir-rtl .chat-message .right,
+.dir-rtl .chat-message .left  {direction:ltr;}
 
 #chat-input-area,
 #chat-input-area table.generaltable,