Index: src/OFZooArchive.m
==================================================================
--- src/OFZooArchive.m
+++ src/OFZooArchive.m
@@ -256,12 +256,14 @@
 	if (_lastHeaderOffset == 0)
 		return;
 
 	offset = [_stream seekToOffset: 0 whence: OFSeekCurrent];
 
-	if (offset < 0 || offset > UINT32_MAX || _lastHeaderLength < 56)
+	if (offset < 0 || (unsigned long long)offset > UINT32_MAX)
 		@throw [OFOutOfRangeException exception];
+
+	OFEnsure(_lastHeaderLength >= 56);
 
 	[_stream seekToOffset: _lastHeaderOffset whence: OFSeekSet];
 	buffer = OFAllocMemory(1, _lastHeaderLength);
 	@try {
 		uint16_t tmp16;
@@ -597,11 +599,11 @@
 	_entry.compressedSize = _bytesWritten;
 	_entry.CRC16 = _CRC16;
 
 	offset = [_stream seekToOffset: 0 whence: OFSeekCurrent];
 
-	if (offset > UINT32_MAX)
+	if ((unsigned long long)offset > UINT32_MAX)
 		@throw [OFOutOfRangeException exception];
 
 	[_stream seekToOffset: *_lastHeaderOffset whence: OFSeekSet];
 	_entry->_dataOffset = (uint32_t)offset;