diff --git a/src/Twilio/APIKey.hs b/src/Twilio/APIKey.hs
index 0d4c310..7809dd6 100644
--- a/src/Twilio/APIKey.hs
+++ b/src/Twilio/APIKey.hs
@@ -20,7 +20,6 @@ module Twilio.APIKey
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 
diff --git a/src/Twilio/Account.hs b/src/Twilio/Account.hs
index b5c8c64..0c5039a 100644
--- a/src/Twilio/Account.hs
+++ b/src/Twilio/Account.hs
@@ -26,7 +26,6 @@ module Twilio.Account
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import Network.URI
diff --git a/src/Twilio/Address.hs b/src/Twilio/Address.hs
index 1719ebe..c56876c 100644
--- a/src/Twilio/Address.hs
+++ b/src/Twilio/Address.hs
@@ -20,7 +20,6 @@ import Control.Error.Safe
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 
 import Control.Monad.Twilio
diff --git a/src/Twilio/Application.hs b/src/Twilio/Application.hs
index eed4e97..184e3eb 100644
--- a/src/Twilio/Application.hs
+++ b/src/Twilio/Application.hs
@@ -20,7 +20,6 @@ module Twilio.Application
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import qualified Data.Text as T
 import Data.Time.Clock
diff --git a/src/Twilio/AuthorizedConnectApp.hs b/src/Twilio/AuthorizedConnectApp.hs
index eb375b2..33ba060 100644
--- a/src/Twilio/AuthorizedConnectApp.hs
+++ b/src/Twilio/AuthorizedConnectApp.hs
@@ -19,7 +19,6 @@ module Twilio.AuthorizedConnectApp
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import qualified Data.Text as T
 import Data.Time.Clock
diff --git a/src/Twilio/AvailablePhoneNumbers.hs b/src/Twilio/AvailablePhoneNumbers.hs
index cf49a0f..6a236d2 100644
--- a/src/Twilio/AvailablePhoneNumbers.hs
+++ b/src/Twilio/AvailablePhoneNumbers.hs
@@ -18,7 +18,6 @@ module Twilio.AvailablePhoneNumbers
 import Control.Applicative
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import qualified Data.Text as T
 
 import Control.Monad.Twilio
diff --git a/src/Twilio/Call.hs b/src/Twilio/Call.hs
index f49df9f..54757cf 100644
--- a/src/Twilio/Call.hs
+++ b/src/Twilio/Call.hs
@@ -24,7 +24,6 @@ import Control.Error.Safe
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import Network.URI
diff --git a/src/Twilio/Call/Feedback.hs b/src/Twilio/Call/Feedback.hs
index 501b042..bf902ab 100644
--- a/src/Twilio/Call/Feedback.hs
+++ b/src/Twilio/Call/Feedback.hs
@@ -24,7 +24,6 @@ import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
 import Data.Data
-import Data.Monoid
 import Data.Scientific
 import Data.Time.Clock
 import GHC.Generics
diff --git a/src/Twilio/Conference.hs b/src/Twilio/Conference.hs
index dff9d91..eac733a 100644
--- a/src/Twilio/Conference.hs
+++ b/src/Twilio/Conference.hs
@@ -21,7 +21,6 @@ module Twilio.Conference
 import Control.Monad
 import Data.Aeson
 import Data.Data
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import GHC.Generics
diff --git a/src/Twilio/Conference/Participant.hs b/src/Twilio/Conference/Participant.hs
index 18b0f31..7b764ec 100644
--- a/src/Twilio/Conference/Participant.hs
+++ b/src/Twilio/Conference/Participant.hs
@@ -19,7 +19,6 @@ module Twilio.Conference.Participant
 import Control.Monad
 import Data.Aeson
 import Data.Data
-import Data.Monoid
 import Data.Time.Clock
 import GHC.Generics
 import Network.URI
diff --git a/src/Twilio/Conference/Participants.hs b/src/Twilio/Conference/Participants.hs
index 090e1ae..9a676ff 100644
--- a/src/Twilio/Conference/Participants.hs
+++ b/src/Twilio/Conference/Participants.hs
@@ -20,7 +20,6 @@ import Control.Applicative
 import Data.Aeson
 import Data.Data
 import Data.Maybe
-import Data.Monoid
 import GHC.Generics
 
 import Twilio.Conference.Participant
diff --git a/src/Twilio/ConnectApp.hs b/src/Twilio/ConnectApp.hs
index ebe8119..5a0c878 100644
--- a/src/Twilio/ConnectApp.hs
+++ b/src/Twilio/ConnectApp.hs
@@ -19,7 +19,6 @@ module Twilio.ConnectApp
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import qualified Data.Text as T
 import Network.URI
diff --git a/src/Twilio/IncomingPhoneNumber.hs b/src/Twilio/IncomingPhoneNumber.hs
index b46de97..322257c 100644
--- a/src/Twilio/IncomingPhoneNumber.hs
+++ b/src/Twilio/IncomingPhoneNumber.hs
@@ -18,7 +18,6 @@ module Twilio.IncomingPhoneNumber
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import Network.URI
diff --git a/src/Twilio/Internal/Request.hs b/src/Twilio/Internal/Request.hs
index dfd4cc2..2e80da0 100644
--- a/src/Twilio/Internal/Request.hs
+++ b/src/Twilio/Internal/Request.hs
@@ -74,5 +74,5 @@ runRequest' credentials (RequestT (FreeT m)) = m >>= \case
           else do
             let body = responseBody response
             body' <- LBS.fromChunks <$> brConsume body
-            print body'
+            -- print body'
             go $ const body' <$> response
diff --git a/src/Twilio/Message.hs b/src/Twilio/Message.hs
index 385ce46..e31a663 100644
--- a/src/Twilio/Message.hs
+++ b/src/Twilio/Message.hs
@@ -21,7 +21,6 @@ module Twilio.Message
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import Network.URI
diff --git a/src/Twilio/Message/Media.hs b/src/Twilio/Message/Media.hs
index 8dcc46e..26c2756 100644
--- a/src/Twilio/Message/Media.hs
+++ b/src/Twilio/Message/Media.hs
@@ -20,7 +20,6 @@ module Twilio.Message.Media
 import Control.Monad
 import Data.Aeson
 import Data.Data
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import GHC.Generics
diff --git a/src/Twilio/Message/MediaList.hs b/src/Twilio/Message/MediaList.hs
index 91337f2..273a631 100644
--- a/src/Twilio/Message/MediaList.hs
+++ b/src/Twilio/Message/MediaList.hs
@@ -21,7 +21,6 @@ import Control.Applicative
 import Data.Aeson
 import Data.Data
 import Data.Maybe
-import Data.Monoid
 import GHC.Generics
 
 import Twilio.Internal.Request
diff --git a/src/Twilio/OutgoingCallerID.hs b/src/Twilio/OutgoingCallerID.hs
index c88d097..0362f61 100644
--- a/src/Twilio/OutgoingCallerID.hs
+++ b/src/Twilio/OutgoingCallerID.hs
@@ -19,7 +19,6 @@ module Twilio.OutgoingCallerID
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import Network.URI
diff --git a/src/Twilio/Queue.hs b/src/Twilio/Queue.hs
index 4815dc7..9adb611 100644
--- a/src/Twilio/Queue.hs
+++ b/src/Twilio/Queue.hs
@@ -22,7 +22,6 @@ import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
 import Data.Data
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import GHC.Generics
diff --git a/src/Twilio/Queue/Member.hs b/src/Twilio/Queue/Member.hs
index 52f48d8..5f47392 100644
--- a/src/Twilio/Queue/Member.hs
+++ b/src/Twilio/Queue/Member.hs
@@ -19,7 +19,6 @@ module Twilio.Queue.Member
 import Control.Monad
 import Data.Aeson
 import Data.Data
-import Data.Monoid
 import Data.Time.Clock
 import GHC.Generics
 import Network.URI
diff --git a/src/Twilio/Queue/Members.hs b/src/Twilio/Queue/Members.hs
index 9564786..b46e9eb 100644
--- a/src/Twilio/Queue/Members.hs
+++ b/src/Twilio/Queue/Members.hs
@@ -20,7 +20,6 @@ import Control.Applicative
 import Data.Aeson
 import Data.Data
 import Data.Maybe
-import Data.Monoid
 import GHC.Generics
 
 import Twilio.Queue.Member
diff --git a/src/Twilio/Recording.hs b/src/Twilio/Recording.hs
index 33036a7..8757ed5 100644
--- a/src/Twilio/Recording.hs
+++ b/src/Twilio/Recording.hs
@@ -20,7 +20,6 @@ import Control.Error.Safe
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Time.Clock
 import Network.URI
 
diff --git a/src/Twilio/ShortCode.hs b/src/Twilio/ShortCode.hs
index fd109f9..8ba6251 100644
--- a/src/Twilio/ShortCode.hs
+++ b/src/Twilio/ShortCode.hs
@@ -18,7 +18,6 @@ module Twilio.ShortCode
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import Network.URI
diff --git a/src/Twilio/Transcription.hs b/src/Twilio/Transcription.hs
index 8246cb4..a559d4d 100644
--- a/src/Twilio/Transcription.hs
+++ b/src/Twilio/Transcription.hs
@@ -22,7 +22,6 @@ import Control.Error.Safe
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import Network.URI
diff --git a/src/Twilio/Types.hs b/src/Twilio/Types.hs
index 8bf3797..2ef7c55 100644
--- a/src/Twilio/Types.hs
+++ b/src/Twilio/Types.hs
@@ -34,7 +34,6 @@ import Control.Monad
 import Control.Monad.Reader.Class
 import Data.Aeson
 import qualified Data.ByteString.Char8 as C
-import Data.Monoid
 import Data.Text (Text)
 import qualified Data.Text as T
 #if MIN_VERSION_http_client(0,5,0)
diff --git a/src/Twilio/Types/SID.hs b/src/Twilio/Types/SID.hs
index 3b35754..81d0fa2 100644
--- a/src/Twilio/Types/SID.hs
+++ b/src/Twilio/Types/SID.hs
@@ -26,7 +26,6 @@ import Data.Bits (countLeadingZeros)
 import Data.Data (Data, Typeable)
 import Data.Hashable (Hashable)
 import Data.Ix (Ix)
-import Data.Monoid ((<>))
 import Data.String (IsString(fromString))
 import Data.Text (Text)
 import qualified Data.Text as T
diff --git a/src/Twilio/Types/SID/TH.hs b/src/Twilio/Types/SID/TH.hs
index 7448f93..843239d 100644
--- a/src/Twilio/Types/SID/TH.hs
+++ b/src/Twilio/Types/SID/TH.hs
@@ -14,7 +14,6 @@ module Twilio.Types.SID.TH
   ( createSID
   ) where
 
-import Data.Monoid ((<>))
 import Language.Haskell.TH
 #if MIN_VERSION_template_haskell(2,11,0)
   ( Bang(..)
diff --git a/src/Twilio/UsageTrigger.hs b/src/Twilio/UsageTrigger.hs
index 01fba7a..1c4561b 100644
--- a/src/Twilio/UsageTrigger.hs
+++ b/src/Twilio/UsageTrigger.hs
@@ -18,7 +18,6 @@ module Twilio.UsageTrigger
 import Control.Monad
 import Control.Monad.Catch
 import Data.Aeson
-import Data.Monoid
 import Data.Text (Text)
 import Data.Time.Clock
 import Network.URI
diff --git a/stack.yaml b/stack.yaml
index 9edcb8b..9da6daf 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -15,7 +15,7 @@
 # resolver:
 #  name: custom-snapshot
 #  location: "./custom-snapshot.yaml"
-resolver: lts-8.20
+resolver: lts-13.2
 
 # User packages to be built.
 # Various formats can be used as shown in the example below.
diff --git a/test/api/Test.hs b/test/api/Test.hs
index c68bea0..f91d670 100644
--- a/test/api/Test.hs
+++ b/test/api/Test.hs
@@ -5,7 +5,6 @@
 module Main where
 
 import Control.Monad.IO.Class
-import Data.Monoid
 import Data.Maybe (fromMaybe)
 import Data.Text (Text, unpack, pack)
 import Network.URI
diff --git a/twilio.cabal b/twilio.cabal
index a32f3c8..8ca84c6 100644
--- a/twilio.cabal
+++ b/twilio.cabal
@@ -88,7 +88,7 @@ library
                        base ==4.*,
                        binary >=0.7,
                        bytestring ==0.10.*,
-                       containers ==0.5.*,
+                       containers >= 0.5.0 && <0.7.0,
                        deepseq >=1,
                        errors >=1,
                        exceptions ==0.*,