diff --git a/ChangeLog b/ChangeLog
index 8ca30b6f01..686ba4510a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Mar 21 01:29:35 2003  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* missing.h: include <stdarg.h> or <varargs.h> if HAVE_VSNPRINTF
+	  is not defined.
+
 Thu Mar 20 18:31:37 2003  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
 
 	* lib/optparse.rb (OptionParser#order!): follow recent change
diff --git a/missing.h b/missing.h
index 33dff9bacc..df4cecc916 100644
--- a/missing.h
+++ b/missing.h
@@ -118,6 +118,11 @@ extern unsigned long strtoul _((char *, char **, int));
 #endif
 
 #ifndef HAVE_VSNPRINTF
+# ifdef HAVE_STDARG_PROTOTYPES
+#  include <stdarg.h>
+# else
+#  include <varargs.h>
+# endif
 extern snprintf __((char *, size_t n, char const *, ...));
 extern vsnprintf _((char *, size_t n, char const *, va_list));
 #endif