diff --git a/ChangeLog b/ChangeLog
index d1031e5a5b..c1562e3679 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri Jul  1 15:50:12 2005  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* missing/erf.c: need to include some headers for some platforms.
+
+	* win32/win32.c (copysign, scalb): define for compatibility with
+	  other platforms. [ruby-dev:26430]
+
 Fri Jul  1 15:37:42 2005  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* missing/crypt.c: modified to make it compilable on platforms
diff --git a/missing/erf.c b/missing/erf.c
index 94a40c552a..c0ab65f881 100644
--- a/missing/erf.c
+++ b/missing/erf.c
@@ -31,6 +31,10 @@
 static char sccsid[] = "@(#)erf.c	8.1 (Berkeley) 6/4/93";
 #endif /* not lint */
 
+#include <stdio.h>
+#include "config.h"
+#include "defines.h"
+
 #if defined(vax)||defined(tahoe)
 
 /* Deal with different ways to concatenate in cpp */
diff --git a/win32/win32.h b/win32/win32.h
index c6aabc42b5..ef4120dd8d 100644
--- a/win32/win32.h
+++ b/win32/win32.h
@@ -216,6 +216,12 @@ extern FILE *rb_w32_fsopen(const char *, const char *, int);
 #ifndef finite
 #define finite(x) _finite(x)
 #endif
+#ifndef copysign
+#define copysign(a, b) _copysign(a, b)
+#endif
+#ifndef scalb
+#define scalb(a, b) _scalb(a, b)
+#endif
 #endif
 
 #if 0 && defined __BORLANDC__