diff --git a/desmume/src/emufat.h b/desmume/src/emufat.h
index 6ecdc8b61..acf30d586 100644
--- a/desmume/src/emufat.h
+++ b/desmume/src/emufat.h
@@ -17,12 +17,12 @@
 //based on Arduino SdFat Library ( http://code.google.com/p/sdfatlib/ )
 //Copyright (C) 2009 by William Greiman
 
-//based on mkdosfs - utility to create FAT/MS-DOS filesystems
-//Copyright (C) 1991 Linus Torvalds <torvalds@klaava.helsinki.fi>
-//Copyright (C) 1992-1993 Remy Card <card@masi.ibp.fr>
-//Copyright (C) 1993-1994 David Hudson <dave@humbug.demon.co.uk>
-//Copyright (C) 1998 H. Peter Anvin <hpa@zytor.com>
-//Copyright (C) 1998-2005 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
+//based on mkdosfs - utility to create FAT/MS-DOS filesystems
+//Copyright (C) 1991 Linus Torvalds <torvalds@klaava.helsinki.fi>
+//Copyright (C) 1992-1993 Remy Card <card@masi.ibp.fr>
+//Copyright (C) 1993-1994 David Hudson <dave@humbug.demon.co.uk>
+//Copyright (C) 1998 H. Peter Anvin <hpa@zytor.com>
+//Copyright (C) 1998-2005 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
 
 
 #ifndef EMUFAT_H
@@ -566,9 +566,11 @@ private:
   // sync of directory entry required
   static const u8 F_FILE_DIR_DIRTY = 0x80;
 // make sure F_OFLAG is ok
-#if ((F_UNUSED | F_FILE_UNBUFFERED_READ | F_FILE_DIR_DIRTY) & F_OFLAG)
-#error flags_ bits conflict
-#endif  // flags_ bits
+
+  void ctassert()
+  {
+	  CTASSERT(!((F_UNUSED | F_FILE_UNBUFFERED_READ | F_FILE_DIR_DIRTY) & F_OFLAG));
+  }
 
   // private data
   u8   flags_;         // See above for definition of flags_ bits