diff --git a/ChangeLog b/ChangeLog
index 5b75160156..f8c28b945d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Dec 13 12:00:09 2010  Tanaka Akira  <akr@fsij.org>
+
+	* file.c: parenthesize macro arguments.
+
 Mon Dec 13 11:21:14 2010  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* io.c (simple_sendfile): added for BSD version of sendfile(2).
diff --git a/file.c b/file.c
index f105a77d76..1630ac1676 100644
--- a/file.c
+++ b/file.c
@@ -72,25 +72,25 @@ int flock(int, int);
 
 /* define system APIs */
 #ifdef _WIN32
-#define STAT(p, s)	rb_w32_ustati64(p, s)
+#define STAT(p, s)	rb_w32_ustati64((p), (s))
 #undef lstat
-#define lstat(p, s)	rb_w32_ustati64(p, s)
+#define lstat(p, s)	rb_w32_ustati64((p), (s))
 #undef access
-#define access(p, m)	rb_w32_uaccess(p, m)
+#define access(p, m)	rb_w32_uaccess((p), (m))
 #undef chmod
-#define chmod(p, m)	rb_w32_uchmod(p, m)
+#define chmod(p, m)	rb_w32_uchmod((p), (m))
 #undef chown
-#define chown(p, o, g)	rb_w32_uchown(p, o, g)
+#define chown(p, o, g)	rb_w32_uchown((p), (o), (g))
 #undef utime
-#define utime(p, t)	rb_w32_uutime(p, t)
+#define utime(p, t)	rb_w32_uutime((p), (t))
 #undef link
-#define link(f, t)	rb_w32_ulink(f, t)
+#define link(f, t)	rb_w32_ulink((f), (t))
 #undef unlink
 #define unlink(p)	rb_w32_uunlink(p)
 #undef rename
-#define rename(f, t)	rb_w32_urename(f, t)
+#define rename(f, t)	rb_w32_urename((f), (t))
 #else
-#define STAT(p, s)	stat(p, s)
+#define STAT(p, s)	stat((p), (s))
 #endif
 
 #if defined(__BEOS__) || defined(__HAIKU__) /* should not change ID if -1 */
@@ -124,7 +124,7 @@ VALUE rb_cFile;
 VALUE rb_mFileTest;
 VALUE rb_cStat;
 
-#define insecure_obj_p(obj, level) (level >= 4 || (level > 0 && OBJ_TAINTED(obj)))
+#define insecure_obj_p(obj, level) ((level) >= 4 || ((level) > 0 && OBJ_TAINTED(obj)))
 
 static VALUE
 file_path_convert(VALUE name)
@@ -1099,7 +1099,7 @@ VALUE
 rb_file_directory_p(VALUE obj, VALUE fname)
 {
 #ifndef S_ISDIR
-#   define S_ISDIR(m) ((m & S_IFMT) == S_IFDIR)
+#   define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
 #endif
 
     struct stat st;
@@ -1121,7 +1121,7 @@ rb_file_pipe_p(VALUE obj, VALUE fname)
 {
 #ifdef S_IFIFO
 #  ifndef S_ISFIFO
-#    define S_ISFIFO(m) ((m & S_IFMT) == S_IFIFO)
+#    define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
 #  endif
 
     struct stat st;
@@ -1148,10 +1148,10 @@ rb_file_symlink_p(VALUE obj, VALUE fname)
 #    define S_ISLNK(m) _S_ISLNK(m)
 #  else
 #    ifdef _S_IFLNK
-#      define S_ISLNK(m) ((m & S_IFMT) == _S_IFLNK)
+#      define S_ISLNK(m) (((m) & S_IFMT) == _S_IFLNK)
 #    else
 #      ifdef S_IFLNK
-#	 define S_ISLNK(m) ((m & S_IFMT) == S_IFLNK)
+#	 define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
 #      endif
 #    endif
 #  endif
@@ -1185,10 +1185,10 @@ rb_file_socket_p(VALUE obj, VALUE fname)
 #    define S_ISSOCK(m) _S_ISSOCK(m)
 #  else
 #    ifdef _S_IFSOCK
-#      define S_ISSOCK(m) ((m & S_IFMT) == _S_IFSOCK)
+#      define S_ISSOCK(m) (((m) & S_IFMT) == _S_IFSOCK)
 #    else
 #      ifdef S_IFSOCK
-#	 define S_ISSOCK(m) ((m & S_IFMT) == S_IFSOCK)
+#	 define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
 #      endif
 #    endif
 #  endif
@@ -1216,7 +1216,7 @@ rb_file_blockdev_p(VALUE obj, VALUE fname)
 {
 #ifndef S_ISBLK
 #   ifdef S_IFBLK
-#	define S_ISBLK(m) ((m & S_IFMT) == S_IFBLK)
+#	define S_ISBLK(m) (((m) & S_IFMT) == S_IFBLK)
 #   else
 #	define S_ISBLK(m) (0)  /* anytime false */
 #   endif
@@ -1242,7 +1242,7 @@ static VALUE
 rb_file_chardev_p(VALUE obj, VALUE fname)
 {
 #ifndef S_ISCHR
-#   define S_ISCHR(m) ((m & S_IFMT) == S_IFCHR)
+#   define S_ISCHR(m) (((m) & S_IFMT) == S_IFCHR)
 #endif
 
     struct stat st;
@@ -1443,7 +1443,7 @@ rb_file_executable_real_p(VALUE obj, VALUE fname)
 }
 
 #ifndef S_ISREG
-#   define S_ISREG(m) ((m & S_IFMT) == S_IFREG)
+#   define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
 #endif
 
 /*
@@ -3171,8 +3171,8 @@ file_expand_path(VALUE fname, VALUE dname, int abs_mode, VALUE result)
 #define EXPAND_PATH_BUFFER() rb_usascii_str_new(0, MAXPATHLEN + 2)
 
 #define check_expand_path_args(fname, dname) \
-    ((fname = rb_get_path(fname)), \
-     (void)(NIL_P(dname) ? dname : (dname = rb_get_path(dname))))
+    (((fname) = rb_get_path(fname)), \
+     (void)(NIL_P(dname) ? (dname) : ((dname) = rb_get_path(dname))))
 
 static VALUE
 file_expand_path_1(VALUE fname)
@@ -5011,7 +5011,7 @@ path_check_0(VALUE path, int execpath)
 #endif
 
 #if ENABLE_PATH_CHECK
-#define fpath_check(path) path_check_0(path, FALSE)
+#define fpath_check(path) path_check_0((path), FALSE)
 #else
 #define fpath_check(path) 1
 #endif