diff --git a/ChangeLog b/ChangeLog
index 3e11bb4902..abe7005a63 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Thu Feb 21 13:37:07 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
+
+	* file.c (RB_MAX_GROUPS): moved to
+	* internal.h (RB_MAX_GROUPS): here.
+
+	* file.c (rb_group_member): use RB_MAX_GROUPS instead of
+	  RUBY_GROUP_MAX. They are the same.
+
 Thu Feb 21 13:15:40 2013  KOSAKI Motohiro  <kosaki.motohiro@gmail.com>
 
 	* file.c (access_internal): removed.
diff --git a/file.c b/file.c
index 819224e856..1cc7f63d18 100644
--- a/file.c
+++ b/file.c
@@ -1013,9 +1013,6 @@ rb_file_lstat(VALUE obj)
 #endif
 }
 
-/* Linux allow 65536 groups and it is maximum value as far as we know. */
-#define RUBY_GROUP_MAX 65536
-
 static int
 rb_group_member(GETGROUPS_T gid)
 {
@@ -1036,7 +1033,7 @@ rb_group_member(GETGROUPS_T gid)
      * accept more larger value.
      * So we don't trunk NGROUPS anymore.
      */
-    while (groups <= RUBY_GROUP_MAX) {
+    while (groups <= RB_MAX_GROUPS) {
 	gary = ALLOCV_N(GETGROUPS_T, v, groups);
 	anum = getgroups(groups, gary);
 	if (anum != groups)
diff --git a/internal.h b/internal.h
index 8630b8bbf3..b5871fcd55 100644
--- a/internal.h
+++ b/internal.h
@@ -191,6 +191,7 @@ VALUE rb_proc_location(VALUE self);
 st_index_t rb_hash_proc(st_index_t hash, VALUE proc);
 
 /* process.c */
+#define RB_MAX_GROUPS (65536)
 
 struct rb_execarg {
     int use_shell;
diff --git a/process.c b/process.c
index c52562274c..34a38cb18e 100644
--- a/process.c
+++ b/process.c
@@ -5432,7 +5432,6 @@ proc_setgid(VALUE obj, VALUE id)
  * HP-UX			   20
  * Windows			 1015
  */
-#define RB_MAX_GROUPS (65536)
 static int _maxgroups = -1;
 static int
 get_sc_ngroups_max(void)