1 files changed, 7 insertions, 4 deletions
diff --git a/lib/tk.rb b/lib/tk.rb
index b932696290..b10274100d 100644
--- a/lib/tk.rb
+++ b/lib/tk.rb
@@ -268,6 +268,13 @@ module TkCore
   end
 
   def mainloop
+    if defined?(Thread)
+      INTERP._eval("proc rb_after {} {
+                      ruby {Thread.pass};
+                      after 200 rb_after
+                    }")
+      INTERP._eval("rb_after")
+    end
     TclTkLib.mainloop
   end
 
@@ -317,10 +324,6 @@ module Tk
     tk_call 'bell'
   end
 
-  def mainloop
-    TclTkLib.mainloop
-  end
-
   module Scrollable
     def xscrollcommand(cmd=Proc.new)
       configure_cmd 'xscrollcommand', cmd