diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 0.1.0.4
+
+- Relax version bounds to encompass `nri-prelude-0.4.0.0`.
+
 # 0.1.0.3
 
 - Relax version bounds to encompass `nri-prelude-0.3.0.0`.
diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,6 +1,6 @@
 BSD 3-Clause License
 
-Copyright (c) 2020, NoRedInk
+Copyright (c) 2021, NoRedInk
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
diff --git a/nri-env-parser.cabal b/nri-env-parser.cabal
--- a/nri-env-parser.cabal
+++ b/nri-env-parser.cabal
@@ -1,13 +1,13 @@
 cabal-version: 1.18
 
--- This file has been generated from package.yaml by hpack version 0.33.0.
+-- This file has been generated from package.yaml by hpack version 0.34.2.
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 31adfc6f20549796404b6185801ed95d74e1e00899f843541f15c3871190cf82
+-- hash: 484714e0aaf74c61be7ce233e5253fb0823a154d51e3158341e5cf9ede2d291f
 
 name:           nri-env-parser
-version:        0.1.0.3
+version:        0.1.0.4
 synopsis:       Read environment variables as settings to build 12-factor apps.
 description:    Please see the README at <https://github.com/NoRedInk/haskell-libraries/tree/trunk/env-parser>.
 category:       Web
@@ -15,7 +15,7 @@
 bug-reports:    https://github.com/NoRedInk/haskell-libraries/issues
 author:         NoRedInk
 maintainer:     haskell-open-source@noredink.com
-copyright:      2020 NoRedInk Corp.
+copyright:      2021 NoRedInk Corp.
 license:        BSD3
 license-file:   LICENSE
 build-type:     Simple
@@ -37,11 +37,11 @@
   hs-source-dirs:
       src
   default-extensions: DataKinds DeriveGeneric FlexibleContexts FlexibleInstances GeneralizedNewtypeDeriving MultiParamTypeClasses NamedFieldPuns NoImplicitPrelude OverloadedStrings PartialTypeSignatures ScopedTypeVariables Strict TypeOperators
-  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wpartial-fields -Wredundant-constraints -Wincomplete-uni-patterns
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wpartial-fields -Wredundant-constraints -Wincomplete-uni-patterns -fplugin=NriPrelude.Plugin
   build-depends:
       base >=4.12.0.0 && <4.15
     , modern-uri >=0.3.1.0 && <0.4
     , network-uri >=2.6.2.0 && <2.8
-    , nri-prelude >=0.1.0.0 && <0.4
+    , nri-prelude >=0.1.0.0 && <0.5
     , text >=1.2.3.1 && <1.3
   default-language: Haskell2010
diff --git a/src/Environment.hs b/src/Environment.hs
--- a/src/Environment.hs
+++ b/src/Environment.hs
@@ -173,12 +173,11 @@
 -- | An environment decoder knows how to read an app's configuration from
 -- environment variables. Check out the @variable@ function to see how you can
 -- begin building decoders.
-data Decoder config
-  = Decoder
-      { -- | The list of @Variable@s that this decoder will read when ran.
-        consumes :: [Variable],
-        readFromEnvironment :: Dict.Dict Text Text -> Result [ParseError] config
-      }
+data Decoder config = Decoder
+  { -- | The list of @Variable@s that this decoder will read when ran.
+    consumes :: [Variable],
+    readFromEnvironment :: Dict.Dict Text Text -> Result [ParseError] config
+  }
   deriving (Functor)
 
 instance Applicative Decoder where
@@ -206,30 +205,27 @@
             fr <*> xr
 
 -- | An environment variable with a description of what it is used for.
-data Variable
-  = Variable
-      { name :: Text,
-        description :: Text,
-        defaultValue :: Text
-      }
+data Variable = Variable
+  { name :: Text,
+    description :: Text,
+    defaultValue :: Text
+  }
   deriving (Show)
 
-data ParseError
-  = ParseError
-      { failingVariable :: Variable,
-        failingReason :: Text
-      }
+data ParseError = ParseError
+  { failingVariable :: Variable,
+    failingReason :: Text
+  }
   deriving (Show)
 
 -- | Describe a decoded variable for informational purposes.
-data DecodedVariable
-  = DecodedVariable
-      { decodedVariable :: Variable,
-        decodedCurrent :: Maybe Text,
-        -- A single environment variable can be decoded by multiple decoders,
-        -- each with their own constraints.
-        decodedErrors :: List Text
-      }
+data DecodedVariable = DecodedVariable
+  { decodedVariable :: Variable,
+    decodedCurrent :: Maybe Text,
+    -- A single environment variable can be decoded by multiple decoders,
+    -- each with their own constraints.
+    decodedErrors :: List Text
+  }
   deriving (Show)
 
 -- | Produce a configuration from a single environment veriable. Usually you