Index: src/OFZIPArchive.m
==================================================================
--- src/OFZIPArchive.m
+++ src/OFZIPArchive.m
@@ -320,10 +320,13 @@
 
 	if (!valid)
 		@throw [OFInvalidFormatException exception];
 
 	_diskNumber = _lastDiskNumber = [_stream readLittleEndianInt16];
+	if (_diskNumber == 0)
+		_diskNumber = _lastDiskNumber = 1;
+
 	_centralDirectoryDisk = [_stream readLittleEndianInt16];
 	_centralDirectoryEntriesInDisk = [_stream readLittleEndianInt16];
 	_centralDirectoryEntries = [_stream readLittleEndianInt16];
 	_centralDirectorySize = [_stream readLittleEndianInt32];
 	_centralDirectoryOffset = [_stream readLittleEndianInt32];