diff --git a/main.lua b/main.lua
index 7c7c1a5..b07c7fa 100644
--- a/main.lua
+++ b/main.lua
@@ -270,6 +270,9 @@ function IrcChatView:appendLine(line, target)
         if self._ui_open and self.scroll_text_w and self.scroll_text_w.text_widget then
             self.scroll_text_w.text_widget:setText(buf)
             self.scroll_text_w:scrollToBottom()
+            if UIManager and self.frame and self.frame.dimen then
+                UIManager:setDirty(self, function() return "ui", self.frame.dimen end)
+            end
         end
     else
         -- increment unread counter for background target