Index: src/OFZIPArchive.m
==================================================================
--- src/OFZIPArchive.m
+++ src/OFZIPArchive.m
@@ -235,11 +235,11 @@
 	if (_diskNumber == 0xFFFF ||
 	    _centralDirectoryDisk == 0xFFFF ||
 	    _centralDirectoryEntriesInDisk == 0xFFFF ||
 	    _centralDirectoryEntries == 0xFFFF ||
 	    _centralDirectorySize == 0xFFFFFFFF ||
-	    _centralDirectoryOffset == -1) {
+	    _centralDirectoryOffset == 0xFFFFFFFF) {
 		int64_t offset64;
 		uint64_t size;
 
 		seekOrThrowInvalidFormat(_stream, offset - 20, SEEK_END);
 

Index: src/OFZIPArchiveEntry.m
==================================================================
--- src/OFZIPArchiveEntry.m
+++ src/OFZIPArchiveEntry.m
@@ -203,11 +203,11 @@
 				_uncompressedSize = of_zip_archive_read_field64(
 				    &ZIP64, &ZIP64Size);
 			if (_compressedSize == 0xFFFFFFFF)
 				_compressedSize = of_zip_archive_read_field64(
 				    &ZIP64, &ZIP64Size);
-			if (_localFileHeaderOffset == -1)
+			if (_localFileHeaderOffset == 0xFFFFFFFF)
 				_localFileHeaderOffset =
 				    of_zip_archive_read_field64(&ZIP64,
 				    &ZIP64Size);
 			if (_startDiskNumber == 0xFFFF)
 				_startDiskNumber = of_zip_archive_read_field32(