diff --git a/src/zippy/ziparchives.nim b/src/zippy/ziparchives.nim
index 2fe5e70..ce31394 100644
--- a/src/zippy/ziparchives.nim
+++ b/src/zippy/ziparchives.nim
@@ -383,7 +383,7 @@ proc openZipArchive*(
         compressedSize: compressedSize,
         uncompressedSize: uncompressedSize,
         uncompressedCrc32: uncompressedCrc32,
-        filePermissions: parseFilePermissions(externalFileAttr.int shr 16)
+        filePermissions: parseFilePermissions((externalFileAttr.uint shr 16).int)
       )
   except IOError as e:
     result.close()