diff --git a/Headers/gnustep/base/NSString.h b/Headers/gnustep/base/NSString.h
index dadc28202..ea70acb92 100644
--- a/Headers/gnustep/base/NSString.h
+++ b/Headers/gnustep/base/NSString.h
@@ -82,6 +82,9 @@ typedef enum _NSStringEncoding
   NSWindowsCP1254StringEncoding = 14,
   NSWindowsCP1250StringEncoding = 15,
   NSISO2022JPStringEncoding = 21,
+  NSMacOSRomanStringEncoding = 30,
+  NSProprietaryStringEncoding = 31,
+
 // GNUstep additions
   NSCyrillicStringEncoding = 22