diff --git a/ChangeLog b/ChangeLog
index 8eb62400e1..3fd1b5db24 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Jun 15 05:12:59 2011  Hidetoshi NAGAI  <nagai@ai.kyutech.ac.jp>
+
+	* ext/tk/tcltklib.c (lib_eventloop_core): revert the last change (it's 
+	  the part for ruby_1_8), and use rb_thread_check_ints() when RUBY_VM
+	  is defined.
+
 Wed Jun 15 04:42:47 2011  Koichi Sasada  <ko1@atdot.net>
 
 	* benchmark/bm_vm3_thread_*.rb: renamed bm_vm3_thread_*.rb to
diff --git a/ext/tk/tcltklib.c b/ext/tk/tcltklib.c
index d27af153a5..f0f0b4a6db 100644
--- a/ext/tk/tcltklib.c
+++ b/ext/tk/tcltklib.c
@@ -2526,11 +2526,11 @@ lib_eventloop_core(check_root, update_flag, check_var, interp)
             rb_thread_schedule();
         }
 
-        DUMP1("trap check & thread scheduling");
-#ifdef RUBY_USE_NATIVE_THREAD
-        /* if (update_flag == 0) CHECK_INTS; */ /*XXXXXXXXXXXXX  TODO !!!! */
-#else
+        DUMP1("check interrupts");
+#if defined(RUBY_USE_NATIVE_THREAD) || defined(RUBY_VM)
 	if (update_flag == 0) rb_thread_check_ints();
+#else
+        if (update_flag == 0) CHECK_INTS;
 #endif
 
     }