diff --git a/lib/SlackBuilder/Config.hs b/lib/SlackBuilder/Config.hs
index d94000c..5a0b791 100644
--- a/lib/SlackBuilder/Config.hs
+++ b/lib/SlackBuilder/Config.hs
@@ -1,3 +1,4 @@
+-- | Configuration file.
 module SlackBuilder.Config
     ( Settings(..)
     , MaintainerSettings(..)
diff --git a/lib/SlackBuilder/Info.hs b/lib/SlackBuilder/Info.hs
index 861193b..9362820 100644
--- a/lib/SlackBuilder/Info.hs
+++ b/lib/SlackBuilder/Info.hs
@@ -1,3 +1,4 @@
+-- | Info file parsing and printing.
 module SlackBuilder.Info
     ( PackageInfo(..)
     , generate
@@ -113,7 +114,7 @@ generate pkg = Lazy.Text.toStrict $ Text.Builder.toLazyText builder
     builder = "PRGNAM=\"" <> Text.Builder.fromString (pkgname pkg) <> "\"\n"
         <> "VERSION=\"" <> Text.Builder.fromText (version pkg) <> "\"\n"
         <> "HOMEPAGE=\"" <> Text.Builder.fromText (homepage pkg) <> "\"\n"
-        <> generateMultiEntry "DOWNLOAD" (render <$> downloads pkg)
+        <> downloadEntry
         <> generateMultiEntry "MD5SUM" (digestToText <$> checksums pkg)
         <> generateMultiEntry "DOWNLOAD_x86_64" (render <$> downloadX64 pkg)
         <> generateMultiEntry "MD5SUM_x86_64" (digestToText <$> checksumX64 pkg)
@@ -122,6 +123,10 @@ generate pkg = Lazy.Text.toStrict $ Text.Builder.toLazyText builder
         <> "EMAIL=\"" <> Text.Builder.fromText (email pkg) <> "\"\n"
     fromByteStringWords = Text.Builder.fromText
         . Text.unwords . fmap Text.decodeUtf8
+    downloadEntry
+        | null $ downloads pkg
+        , not $ null $ downloadX64 pkg = "DOWNLOAD=\"UNSUPPORTED\"\n"
+        | otherwise = generateMultiEntry "DOWNLOAD" $ render <$> downloads pkg
 
 generateMultiEntry :: Text -> [Text] -> Text.Builder
 generateMultiEntry name entries = Text.Builder.fromText name
diff --git a/lib/SlackBuilder/Trans.hs b/lib/SlackBuilder/Trans.hs
index ee9b539..2876691 100644
--- a/lib/SlackBuilder/Trans.hs
+++ b/lib/SlackBuilder/Trans.hs
@@ -1,3 +1,4 @@
+-- | Transformers and exceptions.
 module SlackBuilder.Trans
     ( SlackBuilderException(..)
     , SlackBuilderT(..)
diff --git a/src/Main.hs b/src/Main.hs
index 848d992..b668574 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -49,7 +49,7 @@ import System.Console.ANSI
     )
 import System.Directory (listDirectory, doesDirectoryExist)
 import Control.Monad (filterM)
-import Data.List (isPrefixOf, isSuffixOf)
+import Data.List (isPrefixOf, isSuffixOf, partition)
 
 autoUpdatable :: [Package]
 autoUpdatable =
@@ -78,7 +78,7 @@ autoUpdatable =
                 template = Package.DownloadTemplate
                     $ Package.StaticPlaceholder "https://getcomposer.org/download/"
                     :| [Package.VersionPlaceholder, Package.StaticPlaceholder "/composer.phar"]
-             in Package.Updater latest' $ downloadWithTemplate template
+             in Package.Updater latest' $ downloadWithTemplate template False
         , category = "development"
         , name = "composer"
         , downloaders = mempty
@@ -95,7 +95,7 @@ autoUpdatable =
                     $ Package.StaticPlaceholder "https://github.com/jitsi/jitsi-meet-electron/releases/download/v"
                     :| Package.VersionPlaceholder
                     : [Package.StaticPlaceholder "/jitsi-meet-x86_64.AppImage"]
-             in Package.Updater latest' $ downloadWithTemplate template
+             in Package.Updater latest' $ downloadWithTemplate template False
         , category = "network"
         , name = "jitsi-meet-desktop"
         , downloaders = mempty
@@ -116,7 +116,7 @@ autoUpdatable =
                     $ Package.StaticPlaceholder "https://www.php.net/distributions/php-"
                     :| Package.VersionPlaceholder
                     : [Package.StaticPlaceholder ".tar.xz"]
-             in Package.Updater latest' $ downloadWithTemplate template
+             in Package.Updater latest' $ downloadWithTemplate template False
         , category = "development"
         , name = "php82"
         , downloaders = mempty
@@ -176,7 +176,7 @@ autoUpdatable =
                 template = Package.DownloadTemplate $ pure
                     $ Package.StaticPlaceholder
                         "https://binaries.webex.com/WebexDesktop-Ubuntu-Official-Package/Webex.deb"
-             in Package.Updater latest' $ downloadWithTemplate template
+             in Package.Updater latest' $ downloadWithTemplate template True
         , category = "network"
         , name = "webex"
         , downloaders = mempty
@@ -213,7 +213,7 @@ autoUpdatable =
                     : Package.StaticPlaceholder "/dmd."
                     : Package.VersionPlaceholder
                     : [Package.StaticPlaceholder ".linux.tar.xz"]
-             in Package.Updater latest' $ downloadWithTemplate template
+             in Package.Updater latest' $ downloadWithTemplate template False
         , category = "development"
         , name = "dmd"
         , downloaders = mempty
@@ -244,7 +244,7 @@ autoUpdatable =
                 dscannerURI = [uri|https://github.com/dlang-community/D-Scanner.git|]
                 dcdURI = [uri|https://github.com/dlang-community/DCD.git|]
              in Map.fromList
-                [ ("DUB", Package.Updater latestDub $ downloadWithTemplate dubTemplate)
+                [ ("DUB", Package.Updater latestDub $ downloadWithTemplate dubTemplate False)
                 , ("DSCANNER", Package.Updater latestDscanner $ cloneFromGit dscannerURI "v")
                 , ("DCD", Package.Updater latestDcd $ cloneFromGit dcdURI "v")
                 ]
@@ -327,8 +327,8 @@ cloneFromGit repo tagPrefix packagePath version = do
     (flip . flip Package.Download) (fromJust checksum) False
         <$> liftIO (mkURI $ "https://download.dlackware.com/hosted-sources/" <> name' <> "/" <> downloadFileName)
 
-downloadWithTemplate :: Package.DownloadTemplate -> Text -> Text -> SlackBuilderT Package.Download
-downloadWithTemplate downloadTemplate packagePath version = do
+downloadWithTemplate :: Package.DownloadTemplate -> Bool -> Text -> Text -> SlackBuilderT Package.Download
+downloadWithTemplate downloadTemplate is64' packagePath version = do
     repository' <- SlackBuilderT $ asks repository
     uri' <- liftIO $ Package.renderDownloadWithVersion downloadTemplate version
     let downloadFileName = URI.unRText
@@ -336,11 +336,12 @@ downloadWithTemplate downloadTemplate packagePath version = do
         relativeTarball = packagePath <> "/" <> downloadFileName
         tarball = repository' </> Text.unpack relativeTarball
     checksum <- fromJust <$> download uri' tarball
-    pure $ Package.Download uri' checksum False
+    pure $ Package.Download uri' checksum is64'
 
 reuploadWithTemplate :: Package.DownloadTemplate -> [CmdSpec] -> Text -> Text -> SlackBuilderT Package.Download
 reuploadWithTemplate downloadTemplate commands packagePath version = do
-    Package.Download{ download = uri', md5sum = checksum } <- downloadWithTemplate downloadTemplate packagePath version
+    Package.Download{ download = uri', md5sum = checksum } <-
+        downloadWithTemplate downloadTemplate False packagePath version
     let downloadFileName = URI.unRText
             $ NonEmpty.last $ snd $ fromJust $ URI.uriPath uri'
         relativeTarball = packagePath <> "/" <> downloadFileName
@@ -398,13 +399,16 @@ updatePackage package@Package{..} version info = do
     repository' <- SlackBuilderT $ asks repository
     mainDownload <- renderAndDownload package version
     moreDownloads <- traverse (updateDownload package) downloaders
-    let allDownloads = mainDownload : toList (fst <$> moreDownloads)
+    let (downloads64, allDownloads) = partition (getField @"is64")
+            $ mainDownload : toList (fst <$> moreDownloads)
     let infoFilePath = repository' </> Text.unpack packagePath
             </> (Text.unpack name <.> "info")
         package' = info
             { version = version
             , downloads = getField @"download" <$> allDownloads
             , checksums = getField @"md5sum" <$> allDownloads
+            , downloadX64 = getField @"download" <$> downloads64
+            , checksumX64 = getField @"md5sum" <$> downloads64
             }
     liftIO $ Text.IO.writeFile infoFilePath $ generate package'
     updateSlackBuildVersion packagePath version $ snd <$> moreDownloads