diff --git a/ChangeLog b/ChangeLog
index 2f3e9b3856..fa0c04c477 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Dec  6 19:40:40 2004  WATANABE Hirofumi  <eban@ruby-lang.org>
+
+	* Makefile.in (.y.c): simplify the rule.
+
 Mon Dec  6 17:49:30 2004  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* eval.c (run_trap_eval): add prototype for Microsoft compiler.
diff --git a/Makefile.in b/Makefile.in
index 21469a7fec..685b879dfc 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -6,7 +6,7 @@ srcdir = @srcdir@
 VPATH = $(srcdir):$(srcdir)/missing
 
 CC = @CC@
-YACC = bison -y
+YACC = bison
 PURIFY =
 AUTOCONF = autoconf
 @SET_MAKE@
@@ -158,9 +158,7 @@ lex.c: keywords
 	cp "$(srcdir)/$@" .
 
 .y.c:
-	$(YACC) $(YFLAGS) $<
-	sed '/^#/s|y\.tab\.c|$@|' y.tab.c > $@
-	$(RM) y.tab.c
+	$(YACC) $(YFLAGS) -o $@ $<
 
 .c.@OBJEXT@:
 	$(CC) $(CFLAGS) $(CPPFLAGS) -c $<