@@ -28,10 +28,13 @@
 #import "OFNotImplementedException.h"
 #import "OFNotOpenException.h"
 #import "OFTruncatedDataException.h"
 
 @implementation OFGZIPStream
+@synthesize operatingSystemMadeOn = _operatingSystemMadeOn;
+@synthesize modificationDate = _modificationDate;
+
 + (instancetype)streamWithStream: (OFStream *)stream
 			    mode: (OFString *)mode
 {
 	return [[[self alloc] initWithStream: stream
 					mode: mode] autorelease];
@@ -52,10 +55,12 @@
 			@throw [OFNotImplementedException
 			    exceptionWithSelector: _cmd
 					   object: nil];
 
 		_stream = [stream retain];
+		_operatingSystemMadeOn =
+		    OF_GZIP_STREAM_OPERATING_SYSTEM_UNKNOWN;
 		_CRC32 = ~0;
 	} @catch (id e) {
 		[self release];
 		@throw e;
 	}
@@ -140,16 +145,16 @@
 				return 0;
 
 			_extraFlags = byte;
 			_state++;
 			break;
-		case OF_GZIP_STREAM_OS:
+		case OF_GZIP_STREAM_OPERATING_SYSTEM:
 			if ([_stream readIntoBuffer: &byte
 					     length: 1] < 1)
 				return 0;
 
-			_OS = byte;
+			_operatingSystemMadeOn = byte;
 			_state++;
 			break;
 		case OF_GZIP_STREAM_EXTRA_LENGTH:
 			if (!(_flags & OF_GZIP_STREAM_FLAG_EXTRA)) {
 				_state += 2;