diff --git a/morte.cabal b/morte.cabal
--- a/morte.cabal
+++ b/morte.cabal
@@ -1,5 +1,5 @@
 Name: morte
-Version: 1.4.1
+Version: 1.4.2
 Cabal-Version: >=1.8.0.2
 Build-Type: Simple
 Tested-With: GHC == 7.6.3, GHC == 7.8.4, GHC == 7.10.2
@@ -43,7 +43,7 @@
         Earley             >= 0.10.1.0 && < 0.11 ,
         http-client        >= 0.4.0    && < 0.5  ,
         http-client-tls    >= 0.2.0    && < 0.3  ,
-        microlens          >= 0.2.0.0  && < 0.4  ,
+        microlens          >= 0.2.0.0  && < 0.5  ,
         microlens-mtl      >= 0.1.3.1  && < 0.2  ,
         managed            >= 1.0.0    && < 1.1  ,
         pipes              >= 4.0.0    && < 4.2  ,
diff --git a/src/Morte/Parser.hs b/src/Morte/Parser.hs
--- a/src/Morte/Parser.hs
+++ b/src/Morte/Parser.hs
@@ -13,8 +13,8 @@
 
 import Control.Applicative hiding (Const)
 import Control.Exception (Exception)
-import Control.Monad.Trans.Class (lift)
-import Control.Monad.Trans.Error (Error(..), throwError, runErrorT)
+import Control.Monad.Trans.Class  (lift)
+import Control.Monad.Trans.Except (Except, throwE, runExceptT)
 import Control.Monad.Trans.State.Strict (evalState, get)
 import Data.Monoid
 import Data.Text.Buildable (Buildable(..))
@@ -169,16 +169,9 @@
                 <>  "\n"
                 <>  "Error: Parsing failed\n"
 
-{- This is purely to satisfy the unnecessary `Error` constraint for `ErrorT`
-
-    I will switch to `ExceptT` when the Haskell Platform incorporates
-    `transformers-0.4.*`.
--}
-instance Error ParseError where
-
 -- | Parse an `Expr` from `Text` or return a `ParseError` if parsing fails
 exprFromText :: Text -> Either ParseError (Expr Path)
-exprFromText text = evalState (runErrorT m) (Lexer.P 1 0)
+exprFromText text = evalState (runExceptT m) (Lexer.P 1 0)
   where
     m = do
         (locatedTokens, mtxt) <- lift (Pipes.toListM' (Lexer.lexExpr text))
@@ -186,7 +179,7 @@
             Nothing  -> return ()
             Just txt -> do
                 pos <- lift get
-                throwError (ParseError pos (Lexing txt))
+                throwE (ParseError pos (Lexing txt))
         let (parses, Report _ needed found) =
                 fullParses (parser expr) locatedTokens
         case parses of
@@ -195,4 +188,4 @@
                 let LocatedToken t pos = case found of
                         lt:_ -> lt
                         _    -> LocatedToken Lexer.EOF (P 0 0)
-                throwError (ParseError pos (Parsing t needed))
+                throwE (ParseError pos (Parsing t needed))