diff --git a/ChangeLog b/ChangeLog
index 6f319703cd..0fa3823047 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Feb 18 12:00:58 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* file.c (file_expand_path): suppress a warning.  named magic
+	  numbers.
+
 Wed Feb 18 01:58:11 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/etc/etc.c (sGroup): getgrent may not be available.
diff --git a/file.c b/file.c
index ce7e273eb2..bf0c0b4b53 100644
--- a/file.c
+++ b/file.c
@@ -2661,7 +2661,7 @@ file_expand_path(fname, dname, result)
 		    }
 #if USE_NTFS
 		    else {
-			do *++s; while (istrailinggabage(*s));
+			do ++s; while (istrailinggabage(*s));
 		    }
 #endif
 		    break;
@@ -2712,12 +2712,18 @@ file_expand_path(fname, dname, result)
 
     if (s > b) {
 #if USE_NTFS
+	static const char prime[] = ":$DATA";
+	enum {prime_len = sizeof(prime) -1};
       endpath:
-	if (s > b + 6 && strncasecmp(s - 6, ":$DATA", 6) == 0) {
+	if (s > b + prime_len && strncasecmp(s - prime_len, prime, prime_len) == 0) {
 	    /* alias of stream */
 	    /* get rid of a bug of x64 VC++ */
-	    if (*(s-7) == ':') s -= 7;			/* prime */
-	    else if (memchr(b, ':', s - 6 - b)) s -= 6; /* alternative */
+	    if (*(s - (prime_len+1)) == ':') {
+		s -= prime_len + 1; /* prime */
+	    }
+	    else if (memchr(b, ':', s - prime_len - b)) {
+		s -= prime_len;	/* alternative */
+	    }
 	}
 #endif
 	BUFCHECK(bdiff + (s-b) >= buflen);