diff --git a/ChangeLog b/ChangeLog
index 889294473b..ed4341f813 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Mar 14 16:41:45 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* eval.c (rb_thread_schedule): raise FATAL just once to
+	  THREAD_TO_KILL.
+
 Wed Mar 14 10:41:34 2001  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* eval.c (rb_yield_0): 0 (= Qfalse) is a valid value, so that
diff --git a/eval.c b/eval.c
index 197f6a662b..5d2f0016fe 100644
--- a/eval.c
+++ b/eval.c
@@ -6881,7 +6881,9 @@ struct thread {
     VALUE thread;
 };
 
-#define THREAD_RAISED 0x200
+#define THREAD_RAISED 0x200	 /* temporary flag */
+#define THREAD_TERMINATING 0x400 /* persistent flag */
+#define THREAD_FLAGS_MASK  0x400 /* mask for persistent flags */
 
 #define FOREACH_THREAD_FROM(f,x) x = f; do { x = x->next;
 #define END_FOREACH_FROM(f,x) } while (x != f)
@@ -7033,7 +7035,8 @@ rb_thread_save_context(th)
     th->wrapper = ruby_wrapper;
     th->dyna_vars = ruby_dyna_vars;
     th->block = ruby_block;
-    th->flags = scope_vmode | (rb_trap_immediate<<8);
+    th->flags &= THREAD_FLAGS_MASK;
+    th->flags |= (rb_trap_immediate<<8) | scope_vmode;
     th->iter = ruby_iter;
     th->tag = prot_tag;
     th->tracing = tracing;
@@ -7459,8 +7462,11 @@ rb_thread_schedule()
 
     curr_thread = next;
     if (next->status == THREAD_TO_KILL) {
-	/* execute ensure-clause if any */
-	rb_thread_restore_context(next, RESTORE_FATAL);
+	if (!(next->flags & THREAD_TERMINATING)) {
+	    next->flags |= THREAD_TERMINATING;
+	    /* terminate; execute ensure-clause if any */
+	    rb_thread_restore_context(next, RESTORE_FATAL);
+	}
     }
     rb_thread_restore_context(next, RESTORE_NORMAL);
 }
diff --git a/lib/thread.rb b/lib/thread.rb
index d4b6ad6ec1..559cd95a8a 100644
--- a/lib/thread.rb
+++ b/lib/thread.rb
@@ -185,7 +185,7 @@ class Queue
     end
   end
   def shift(non_block=false)
-    pop(non_block=false)
+    pop(non_block)
   end
   alias deq shift