diff --git a/ChangeLog b/ChangeLog
index 15fa12ec02..ec53ed9423 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,7 @@
-Tue Nov  9 21:13:02 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Tue Nov  9 21:14:54 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* configure.in (AC_FUNC_GETPGRP, AC_FUNC_SETPGRP): no need when
+	  not used.
 
 	* configure.in (EXPORT_PREFIX): check generic prefix.
 
diff --git a/configure.in b/configure.in
index 808bba8a41..5dede8d33e 100644
--- a/configure.in
+++ b/configure.in
@@ -986,7 +986,6 @@ main()
 		ac_cv_func_ftello=yes
 		ac_cv_lib_crypt_crypt=no
 		ac_cv_func_getpgrp_void=no
-		ac_cv_func_setpgrp_void=yes
 		ac_cv_func_memcmp_working=yes
 		ac_cv_lib_dl_dlopen=no
 		rb_cv_binary_elf=no
@@ -1510,8 +1509,12 @@ main()
   fi
 fi
 
+if test "$ac_cv_func_getpgid" = no; then
 AC_FUNC_GETPGRP
+fi
+if test "$ac_cv_func_setpgid:$ac_cv_func_setpgrp" = no:yes; then
 AC_FUNC_SETPGRP
+fi
 
 AC_C_BIGENDIAN
 AC_C_CONST