diff --git a/ChangeLog b/ChangeLog
index 3e73da9..92cc1a7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jun 18 00:45:50 2009  Minero Aoki  <aamine@loveruby.net>
+
+	* lib/Makefile: use 's' option to create index.
+
 Sun Jun 14 23:44:47 2009  Minero Aoki  <aamine@loveruby.net>
 
 	* net/loveruby/cflat/compiler/Options.java
diff --git a/lib/Makefile b/lib/Makefile
index 2914831..cf01739 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -5,6 +5,7 @@ OBJS = stdarg.o alloca.o
 
 CC = gcc
 CFLAGS = -Wall
+AR_CREATE = ar crs
 
 .SUFFIXES:
 .SUFFIXES: .cb .s .o
@@ -15,7 +16,7 @@ CFLAGS = -Wall
 	$(CBC) -c $<
 
 $(TARGET): $(OBJS)
-	ar cr $(TARGET) $(OBJS)
+	$(AR_CREATE) $(TARGET) $(OBJS)
 
 stdarg.o: stdarg.cb