diff --git a/ChangeLog b/ChangeLog
index ec90c7c329..2c4b618a92 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Mon Sep  5 19:32:15 2011  CHIKANAGA Tomoyuki  <nagachika00@gmail.com>
+
+	* Makefile.in (INSNS): change command line option -Ks to -Ku for
+	  generate *.inc. because insns.def encoding has been changed SJIS to
+	  UTF-8. if $BASERUBY is 1.9, -Ks cause an error. [Feature #5128]
+
 Mon Sep  5 18:10:56 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* transcode.c (rb_econv_binmode): newline decorators are
diff --git a/Makefile.in b/Makefile.in
index bcdaf5f7a9..6b12187454 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -382,4 +382,4 @@ $(INSNS): $(srcdir)/insns.def vm_opts.h \
 	  $(srcdir)/defs/opt_operand.def $(srcdir)/defs/opt_insn_unif.def \
 	  $(srcdir)/tool/instruction.rb $(srcdir)/tool/insns2vm.rb
 	$(ECHO) generating $@
-	$(Q) $(BASERUBY) -Ks $(srcdir)/tool/insns2vm.rb $(INSNS2VMOPT) $@
+	$(Q) $(BASERUBY) -Ku $(srcdir)/tool/insns2vm.rb $(INSNS2VMOPT) $@