diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Changelog for wai-extra
 
+## 3.1.16
+
+* Substituted `data-default-class` for `data-default` [#1010](https://github.com/yesodweb/wai/pull/1010)
+
 ## 3.1.15
 
 * Added `validateHeadersMiddleware` for validating response headers set by the application [#990](https://github.com/yesodweb/wai/pull/990).
diff --git a/Network/Wai/Middleware/Gzip.hs b/Network/Wai/Middleware/Gzip.hs
--- a/Network/Wai/Middleware/Gzip.hs
+++ b/Network/Wai/Middleware/Gzip.hs
@@ -51,7 +51,7 @@
 import qualified Data.ByteString.Char8 as S8
 import Data.ByteString.Lazy.Internal (defaultChunkSize)
 import Data.Char (isAsciiLower, isAsciiUpper, isDigit)
-import Data.Default.Class (Default (..))
+import Data.Default (Default (..))
 import Data.Function (fix)
 import Data.Maybe (isJust)
 import qualified Data.Set as Set
diff --git a/Network/Wai/Middleware/RequestLogger.hs b/Network/Wai/Middleware/RequestLogger.hs
--- a/Network/Wai/Middleware/RequestLogger.hs
+++ b/Network/Wai/Middleware/RequestLogger.hs
@@ -38,7 +38,7 @@
 import Data.ByteString.Char8 (pack)
 import qualified Data.ByteString.Char8 as S8
 import qualified Data.ByteString.Lazy as LBS
-import Data.Default.Class (Default (def))
+import Data.Default (Default (def))
 import Data.IORef
 import Data.Maybe (fromMaybe, isJust, mapMaybe)
 #if __GLASGOW_HASKELL__ < 804
diff --git a/Network/Wai/Middleware/ValidateHeaders.hs b/Network/Wai/Middleware/ValidateHeaders.hs
--- a/Network/Wai/Middleware/ValidateHeaders.hs
+++ b/Network/Wai/Middleware/ValidateHeaders.hs
@@ -6,12 +6,12 @@
 --
 -- 'validateHeadersMiddleware' enforces these constraints for response headers by responding with a 500 Internal Server Error when an offending character is present. This is meant to catch programmer errors early on and reduce attack surface.
 module Network.Wai.Middleware.ValidateHeaders
-    -- * Middleware
-    ( validateHeadersMiddleware
-    -- * Settings
+    ( -- * Middleware
+      validateHeadersMiddleware
+      -- * Settings
     , ValidateHeadersSettings (..)
     , defaultValidateHeadersSettings
-    -- * Types
+      -- * Types
     , InvalidHeader (..)
     , InvalidHeaderReason (..)
     ) where
@@ -39,11 +39,11 @@
             Nothing -> respond response
 
 -- | Configuration for 'validateHeadersMiddleware'.
--- 
+--
 -- @since 3.1.15
 data ValidateHeadersSettings = ValidateHeadersSettings
-  -- | Called when an invalid header is present.
-  { onInvalidHeader :: InvalidHeader -> Middleware
+  { -- | Called when an invalid header is present.
+    onInvalidHeader :: InvalidHeader -> Middleware
   }
 
 -- | Default configuration for 'validateHeadersMiddleware'.
@@ -123,7 +123,7 @@
         , "In header '"
         , BSL.fromStrict $ original headerName
         , "' with value '"
-        , BSL.fromStrict $ headerValue
+        , BSL.fromStrict headerValue
         , "': "
         , showReason reason
         , "\nYou are seeing this error message because validateHeadersMiddleware is enabled."
diff --git a/wai-extra.cabal b/wai-extra.cabal
--- a/wai-extra.cabal
+++ b/wai-extra.cabal
@@ -1,5 +1,5 @@
 Name:                wai-extra
-Version:             3.1.15
+Version:             3.1.16
 Synopsis:            Provides some basic WAI handlers and middleware.
 description:
   Provides basic WAI handler and middleware functionality:
@@ -110,7 +110,7 @@
                    , case-insensitive          >= 0.2
                    , containers
                    , cookie
-                   , data-default-class
+                   , data-default
                    , directory                 >= 1.2.7.0
                    , fast-logger               >= 2.4.5
                    , http-types                >= 0.7