diff --git a/frontend/ui/uimanager.lua b/frontend/ui/uimanager.lua
index 74d8df49f..9d2c79ea4 100644
--- a/frontend/ui/uimanager.lua
+++ b/frontend/ui/uimanager.lua
@@ -249,7 +249,9 @@ function UIManager:setDirty(widget, refresh_type)
     if not refresh_type then
         refresh_type = "auto"
     end
-    self._dirty[widget] = refresh_type
+    if widget then
+        self._dirty[widget] = refresh_type
+    end
 end
 
 function UIManager:insertZMQ(zeromq)
diff --git a/frontend/ui/widget/button.lua b/frontend/ui/widget/button.lua
index 68a6e3f03..714a652cb 100644
--- a/frontend/ui/widget/button.lua
+++ b/frontend/ui/widget/button.lua
@@ -147,7 +147,7 @@ function Button:showHide(show)
 end
 
 function Button:onTapSelect()
-    if self.enabled then
+    if self.enabled and self.callback then
         self[1].invert = true
         UIManager:setDirty(self.show_parent, "partial")
         UIManager:scheduleIn(0.1, function()