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diff --git a/overlays/spm/server/Data/UUID/Instances.hs b/overlays/spm/server/Data/UUID/Instances.hs
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+++ b/overlays/spm/server/Data/UUID/Instances.hs
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+{-# OPTIONS_GHC -fno-warn-orphans #-}
+{-# LANGUAGE OverloadedStrings #-}
+
+module Data.UUID.Instances () where
+
+import Prelude
+import Database.Persist
+import Database.Persist.Sql
+import Data.UUID (UUID)
+import qualified Data.UUID as UUID
+
+import qualified Data.ByteString.Char8 as CBS
+import qualified Data.Text as Text
+
+import Web.PathPieces
+  
+
+instance PersistField UUID where
+  toPersistValue = PersistLiteralEscaped . CBS.pack . UUID.toString
+  fromPersistValue (PersistLiteralEscaped uuidB8) =
+    case UUID.fromString $ CBS.unpack uuidB8 of
+      Just uuid -> Right uuid
+      Nothing   -> Left "Invalid UUID"
+  fromPersistValue v = Left $ "Expected PersistLiteral but got ‘" <> Text.pack (show v) <> "’"
+
+instance PersistFieldSql UUID where
+  sqlType _ = SqlOther "uuid"
+
+instance PathPiece UUID where
+  toPathPiece = Text.pack . UUID.toString
+  fromPathPiece = UUID.fromString . Text.unpack