Index: src/OFZooArchive.h
==================================================================
--- src/OFZooArchive.h
+++ src/OFZooArchive.h
@@ -31,10 +31,11 @@
 	OF_KINDOF(OFStream *) _stream;
 	uint_least8_t _mode;
 	OFStringEncoding _encoding;
 	uint16_t _minVersionNeeded;
 	uint8_t _headerType;
+	OFString *_Nullable _archiveComment;
 	OFZooArchiveEntry *_Nullable _currentEntry;
 #ifdef OF_ZOO_ARCHIVE_M
 @public
 #endif
 	OFStream *_Nullable _lastReturnedStream;
@@ -46,10 +47,15 @@
 /**
  * @brief The encoding to use for the archive. Defaults to UTF-8.
  */
 @property (nonatomic) OFStringEncoding encoding;
 
+/**
+ * @brief The archive comment.
+ */
+@property OF_NULLABLE_PROPERTY (copy, nonatomic) OFString *archiveComment;
+
 /**
  * @brief Creates a new OFZooArchive object with the specified stream.
  *
  * @param stream A stream from which the Zoo archive will be read.
  *		 This needs to be an OFSeekableStream. For writing, the stream

Index: src/OFZooArchive.m
==================================================================
--- src/OFZooArchive.m
+++ src/OFZooArchive.m
@@ -170,19 +170,21 @@
 - (void)dealloc
 {
 	if (_stream != nil)
 		[self close];
 
+	[_archiveComment release];
 	[_currentEntry release];
 
 	[super dealloc];
 }
 
 - (void)of_readArchiveHeader
 {
 	char headerText[20];
-	uint32_t firstFileOffset;
+	uint32_t firstFileOffset, commentOffset;
+	uint16_t commentLength;
 
 	[_stream readIntoBuffer: headerText exactLength: 20];
 
 	if ([_stream readLittleEndianInt32] != 0xFDC4A7DC)
 		@throw [OFInvalidFormatException exception];
@@ -199,13 +201,42 @@
 						_minVersionNeeded & 0xFF]];
 
 	if ((_headerType = [_stream readInt8]) > 1)
 		@throw [OFUnsupportedVersionException exceptionWithVersion:
 		    [OFString stringWithFormat: @"%" PRIu8, _headerType]];
+
+	commentOffset = [_stream readLittleEndianInt32];
+	commentLength = [_stream readLittleEndianInt16];
+
+	if (commentOffset > 0) {
+		[_stream seekToOffset: commentOffset whence: OFSeekSet];
+		_archiveComment = [_stream readStringWithLength: commentLength
+						       encoding: _encoding];
+	}
 
 	[_stream seekToOffset: firstFileOffset whence: OFSeekSet];
 }
+
+- (OFString *)archiveComment
+{
+	return _archiveComment;
+}
+
+- (void)setArchiveComment: (OFString *)comment
+{
+	void *pool = objc_autoreleasePoolPush();
+	OFString *old;
+
+	if ([comment cStringLengthWithEncoding: _encoding] > UINT16_MAX)
+		@throw [OFOutOfRangeException exception];
+
+	old = _archiveComment;
+	_archiveComment = [comment copy];
+	[old release];
+
+	objc_autoreleasePoolPop(pool);
+}
 
 - (OFZooArchiveEntry *)nextEntry
 {
 	if (_mode != modeRead)
 		@throw [OFInvalidArgumentException exception];
@@ -294,25 +325,37 @@
 	if (entry.compressionMethod != 0)
 		@throw [OFNotImplementedException exceptionWithSelector: _cmd
 								 object: self];
 
 	if (_lastHeaderOffset == 0) {
+		uint16_t commentLength =
+		    [_archiveComment cStringLengthWithEncoding: _encoding];
+
 		/* First file - write header. */
 		[_stream writeBuffer: "ObjFW Zoo Archive.\x1F" length: 20];
 		[_stream writeLittleEndianInt32: 0xFDC4A7DC];
-		[_stream writeLittleEndianInt32: 42];
-		[_stream writeLittleEndianInt32: -42];
+		[_stream writeLittleEndianInt32: 42 + commentLength];
+		[_stream writeLittleEndianInt32: -(42 + commentLength)];
 		/* TODO: Increase to 0x201 once we add compressed files. */
 		[_stream writeBigEndianInt16: 0x200];
 		/* Header type */
 		[_stream writeInt8: 1];
-		/* Archive comment offset */
-		[_stream writeLittleEndianInt32: 0];
-		/* Archive comment length */
-		[_stream writeLittleEndianInt16: 0];
+
+		if (_archiveComment != nil) {
+			[_stream writeLittleEndianInt32: 42];
+			[_stream writeLittleEndianInt16: commentLength];
+		} else {
+			[_stream writeLittleEndianInt32: 0];
+			[_stream writeLittleEndianInt16: 0];
+		}
+
 		/* Version flag */
 		[_stream writeInt8: 0];
+
+		if (_archiveComment != nil)
+			[_stream writeString: _archiveComment
+				    encoding: _encoding];
 	} else
 		[self of_fixUpLastHeader];
 
 	@try {
 		[_lastReturnedStream close];