diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,10 @@
 # wai-app-static changelog
 
+## 3.1.9.1
+
+* Backported a patch to not need `crypton` as a dependency.
+  Instead, just depend on `base64-bytestring` and `cryptohash-md5`.
+
 ## 3.1.9
 
 * Added `NoCache` constructor to `MaxAge` [#977](https://github.com/yesodweb/wai/pull/977)
diff --git a/WaiAppStatic/Storage/Embedded/Runtime.hs b/WaiAppStatic/Storage/Embedded/Runtime.hs
--- a/WaiAppStatic/Storage/Embedded/Runtime.hs
+++ b/WaiAppStatic/Storage/Embedded/Runtime.hs
@@ -17,13 +17,8 @@
 import qualified Data.Text as T
 import qualified Network.Wai as W
 import WaiAppStatic.Types
-#ifdef MIN_VERSION_crypton
-import Crypto.Hash (hash, MD5, Digest)
-import Data.ByteArray.Encoding
-#else
 import Crypto.Hash.MD5 (hash)
 import Data.ByteString.Base64 (encode)
-#endif
 import System.FilePath (isPathSeparator)
 import WaiAppStatic.Storage.Filesystem (defaultFileServerSettings)
 
@@ -62,7 +57,7 @@
             { fileGetSize = fromIntegral $ S.length bs
             , fileToResponse = \s h -> W.responseBuilder s h $ byteString bs
             , fileName = name
-            , fileGetHash = return $ Just $ runHash bs
+            , fileGetHash = return $ Just $ encode $ hash bs
             , fileGetModified = Nothing
             }
 
@@ -100,13 +95,6 @@
         { fileGetSize = fromIntegral $ S.length bs
         , fileToResponse = \s h -> W.responseBuilder s h $ byteString bs
         , fileName = name
-        , fileGetHash = return $ Just $ runHash bs
+        , fileGetHash = return $ Just $ encode $ hash bs
         , fileGetModified = Nothing
         }
-
-runHash :: ByteString -> ByteString
-#ifdef MIN_VERSION_crypton
-runHash = convertToBase Base64 . (hash :: S.ByteString -> Digest MD5)
-#else
-runHash = encode . hash
-#endif
diff --git a/WaiAppStatic/Storage/Filesystem.hs b/WaiAppStatic/Storage/Filesystem.hs
--- a/WaiAppStatic/Storage/Filesystem.hs
+++ b/WaiAppStatic/Storage/Filesystem.hs
@@ -37,13 +37,8 @@
 import Util
 import WaiAppStatic.Listing
 import WaiAppStatic.Types
-#ifdef MIN_VERSION_crypton
-import Data.ByteArray.Encoding
-import Crypto.Hash (hashlazy, MD5, Digest)
-#else
 import Data.ByteString.Base64 (encode)
 import Crypto.Hash.MD5 (hashlazy)
-#endif
 import qualified Data.ByteString.Lazy as BL (hGetContents)
 import qualified Data.Text as T
 
@@ -157,13 +152,8 @@
 hashFile :: FilePath -> IO ByteString
 hashFile fp = withBinaryFile fp ReadMode $ \h -> do
     f <- BL.hGetContents h
-#ifdef MIN_VERSION_crypton
-    let !hash = hashlazy f :: Digest MD5
-    return $ convertToBase Base64 hash
-#else
     let !hash = hashlazy f
     return . encode $ hash
-#endif
 
 hashFileIfExists :: ETagLookup
 hashFileIfExists fp = do
diff --git a/wai-app-static.cabal b/wai-app-static.cabal
--- a/wai-app-static.cabal
+++ b/wai-app-static.cabal
@@ -1,5 +1,5 @@
 name:            wai-app-static
-version:         3.1.9
+version:         3.1.9.1
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>
@@ -24,10 +24,6 @@
     Description:   print debug info
     Default:       False
 
-Flag crypton
-    Description:   Use the crypton library for MD5 computation
-    Default:       True
-
 library
     default-language: Haskell2010
     build-depends:   base                      >= 4.12     && < 5
@@ -53,11 +49,7 @@
                    , wai-extra                 >= 3.0      && < 3.2
                    , optparse-applicative      >= 0.7
                    , warp                      >= 3.0.11   && < 3.5
-    if flag(crypton)
-      build-depends: crypton                   >= 0.6
-                   , memory                    >= 0.7
-    else
-      build-depends: base64-bytestring         >= 0.1
+                   , base64-bytestring         >= 0.1
                    , cryptohash-md5            >= 0.11.101
 
     exposed-modules: Network.Wai.Application.Static
@@ -110,4 +102,4 @@
 
 source-repository head
   type:     git
-  location: git://github.com/yesodweb/wai.git
+  location: https://github.com/yesodweb/wai.git