diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -41,3 +41,8 @@
 ## 0.1.6.0
 
 * Fix: use provided content-type
+
+
+## 0.1.7.0
+
+* Pass old headers to new response when contentType header be added in `newResponse`.
diff --git a/servant-errors.cabal b/servant-errors.cabal
--- a/servant-errors.cabal
+++ b/servant-errors.cabal
@@ -1,6 +1,6 @@
 cabal-version:       2.2
 name:                servant-errors
-version:             0.1.6.0
+version:             0.1.7.0
 synopsis:            Servant Errors wai-middlware
 description:         A Wai middleware that uniformly structures errors with in a servant application. The library assumes all HTTP responses with status code greater than 200 and without an HTTP content type are error responses. This assumption is derived from servant server error handling implementation.
 
@@ -18,6 +18,7 @@
 tested-with:         GHC == 8.4.4
                    , GHC == 8.6.5
                    , GHC == 8.8.3
+                   , GHC == 8.8.4
 
 
 source-repository head
@@ -27,7 +28,7 @@
 common common-options
   build-depends:       base  >= 4.10.0.0 && < 4.15
                      , base-compat >= 0.9.0
-                     , aeson >= 1.3
+                     , aeson >= 1.3 && < 1.6
                      , text  >= 1.2
                      , wai   >= 3.2
 
diff --git a/src/Network/Wai/Middleware/Servant/Errors.hs b/src/Network/Wai/Middleware/Servant/Errors.hs
--- a/src/Network/Wai/Middleware/Servant/Errors.hs
+++ b/src/Network/Wai/Middleware/Servant/Errors.hs
@@ -164,10 +164,11 @@
   -> IO Response
 newResponse status@(Status code statusMsg) response = do
   body <- responseBody response
-  let header = (hContentType,  M.renderHeader $ contentType (Proxy @ctyp) )
+  let oldHeaders = responseHeaders response
+  let newHeaders = (hContentType,  M.renderHeader $ contentType (Proxy @ctyp)) : oldHeaders
       content = ErrorMsg . cs $ if body == mempty then statusMsg else body
       newContent = encodeError @ctyp @opts (StatusCode code) content
-  return $ responseLBS status [header] newContent
+  return $ responseLBS status newHeaders newContent
 
 -- | 'responseBody' extracts response body from the servant server response.
 responseBody :: Response -> IO B.ByteString