diff --git a/Codec/Archive/Zip/Conduit/Types.hs b/Codec/Archive/Zip/Conduit/Types.hs
index dfcbe4a..a94ba2e 100644
--- a/Codec/Archive/Zip/Conduit/Types.hs
+++ b/Codec/Archive/Zip/Conduit/Types.hs
@@ -9,7 +9,7 @@ import           Data.Semigroup (Semigroup(..))
 import           Data.String (IsString(..))
 import           Data.Time.LocalTime (LocalTime)
 import           Data.Typeable (Typeable)
-import           Data.Word (Word64)
+import           Data.Word (Word32, Word64)
 
 -- |Errors thrown during zip file processing
 newtype ZipError = ZipError String
@@ -32,6 +32,7 @@ data ZipEntry = ZipEntry
   { zipEntryName :: ByteString -- ^File name (in posix format, no leading slashes), usually utf-8 encoded, with a trailing slash for directories
   , zipEntryTime :: LocalTime -- ^Modification time
   , zipEntrySize :: Maybe Word64 -- ^Size of file data (if known); checked on zipping and also used as hint to enable zip64
+  , zipEntryExternalFileAttributes :: Word32 -- ^External file attributes (permissions).
   } deriving (Eq, Show)
 
 -- |The data contents for a 'ZipEntry'. For empty entries (e.g., directories), use 'mempty'.
diff --git a/Codec/Archive/Zip/Conduit/UnZip.hs b/Codec/Archive/Zip/Conduit/UnZip.hs
index 95af05a..7b677c9 100644
--- a/Codec/Archive/Zip/Conduit/UnZip.hs
+++ b/Codec/Archive/Zip/Conduit/UnZip.hs
@@ -219,6 +219,7 @@ unZipStream = next where
         { zipEntryName = name
         , zipEntryTime = time
         , zipEntrySize = if testBit gpf 3 then Nothing else Just extZip64USize
+        , zipEntryExternalFileAttributes = 0
         }
       , fileDecompress = dcomp
       , fileCSize = extZip64CSize
diff --git a/Codec/Archive/Zip/Conduit/Zip.hs b/Codec/Archive/Zip/Conduit/Zip.hs
index 5422f05..c3246d5 100644
--- a/Codec/Archive/Zip/Conduit/Zip.hs
+++ b/Codec/Archive/Zip/Conduit/Zip.hs
@@ -189,7 +189,7 @@ zipStream ZipOptions{..} = execStateC 0 $ do
       P.putWord16le 0 -- comment length
       P.putWord16le 0 -- disk number
       P.putWord16le 0 -- internal file attributes
-      P.putWord32le 0 -- external file attributes
+      P.putWord32le zipEntryExternalFileAttributes -- external file attributes
       P.putWord32le $ if o64 then maxBound32 else fromIntegral off
       P.putByteString zipEntryName
       when a64 $ do
diff --git a/cmd/zip.hs b/cmd/zip.hs
index d29f909..d2ede75 100644
--- a/cmd/zip.hs
+++ b/cmd/zip.hs
@@ -46,6 +46,7 @@ generate (p:paths) = do
         { zipEntryName = BSC.pack $ dropWhile ('/' ==) p
         , zipEntryTime = utcToLocalTime utc t -- FIXME: timezone
         , zipEntrySize = Nothing
+        , zipEntryExternalFileAttributes = 0
         }
   isd <- liftIO $ doesDirectoryExist p
   if isd
diff --git a/stack.yaml b/stack.yaml
index 7af5a28..be18c39 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -2,3 +2,6 @@ resolver: lts-11.1
 packages:
 - '.'
 extra-deps: []
+nix:
+  packages:
+    - zlib