diff --git a/Database/Vault/KVv2/Client.hs b/Database/Vault/KVv2/Client.hs
--- a/Database/Vault/KVv2/Client.hs
+++ b/Database/Vault/KVv2/Client.hs
@@ -61,7 +61,7 @@
 -- >λ: vaultConnect (Just "https://vault.local.lan:8200/") "/secret" Nothing False
 --
 vaultConnect
-  :: Maybe String                       -- ^ Use 'Just' this string as Vault address or get it from variable environment VAULT_ADDR
+  :: Maybe String                       -- ^ Use 'Just' this Vault server address, or get it from environment variable VAULT_ADDR
   -> String                             -- ^ KV engine path
   -> Maybe VaultToken                   -- ^ Use 'Just' this 'VaultToken' or get it from $HOME/.vaut-token
   -> Bool                               -- ^ Disable certificate validation
@@ -75,9 +75,7 @@
               , settingUseServerName                = True
               }
             Nothing
-  va <- case mva of
-          Just va -> return (Just va)
-          Nothing -> lookupEnv "VAULT_ADDR"
+  va <- if M.isJust mva then return mva else lookupEnv "VAULT_ADDR"
   evt <- case mvt of
            Just t  -> return (Right $ C.pack t)
            Nothing -> do
@@ -109,7 +107,7 @@
   -> Int                        -- ^ Max versions
   -> Bool                       -- ^ CAS required
   -> IO (Either String A.Value)
-kvEngineConfig vc@VaultConnection{..} =
+kvEngineConfig vc@VaultConnection{} =
   configR ["POST ", show vc, "/config"] vc
 
 -- | Override default secret settings for the given secret.
@@ -119,7 +117,7 @@
   -> Int                        -- ^ Max versions
   -> Bool                       -- ^ CAS required
   -> IO (Either String A.Value)
-secretConfig vc@VaultConnection{..} SecretPath{..} =
+secretConfig vc@VaultConnection{} SecretPath{..} =
   configR ["POST ", show vc, "/metadata/", path] vc
 
 -- | Get a secret from Vault. Give 'Just' the 'SecretVersion'
@@ -158,7 +156,7 @@
   -> SecretPath
   -> SecretVersions
   -> IO (Maybe Error)
-deleteSecretVersions vc@VaultConnection{..} SecretPath{..} svs =
+deleteSecretVersions vc@VaultConnection{} SecretPath{..} svs =
   maybeError <$> secretVersionsR ["POST ", show vc, "/delete/", path] vc svs
 
 unDeleteSecretVersions
@@ -166,7 +164,7 @@
   -> SecretPath
   -> SecretVersions
   -> IO (Maybe Error)
-unDeleteSecretVersions vc@VaultConnection{..} SecretPath{..} svs =
+unDeleteSecretVersions vc@VaultConnection{} SecretPath{..} svs =
   maybeError <$> secretVersionsR ["POST ", show vc, "/undelete/", path] vc svs
 
 -- | Permanently delete a secret, i.e. all its versions and metadata.
@@ -182,7 +180,7 @@
   -> SecretPath
   -> SecretVersions
   -> IO (Either String A.Value)
-destroySecretVersions vc@VaultConnection{..} SecretPath{..} =
+destroySecretVersions vc@VaultConnection{} SecretPath{..} =
   secretVersionsR ["POST ", show vc, "/destroy/", path] vc
 
 -- | Get list of secrets and folders at the given location.
diff --git a/gothic.cabal b/gothic.cabal
--- a/gothic.cabal
+++ b/gothic.cabal
@@ -1,52 +1,51 @@
-name:                gothic
-version:             0.1.5
-synopsis:            A Haskell Vault KVv2 secret engine client
-description:         A Haskell HashiCorp Vault KVv2 secret engine client library
-homepage:            https://github.com/MichelBoucey/gothic
-license:             BSD3
-license-file:        LICENSE
-author:              Michel Boucey
-maintainer:          michel.boucey@gmail.com
-copyright:           (c) 2019-2020 - Michel Boucey
-category:            DevOps, Security, Database
-build-type:          Simple
-cabal-version:       >=1.10
-extra-source-files:  ReadMe.md
-
-Tested-With: GHC ==8.4.3 || ==8.6.5 || ==8.8.1
+cabal-version:      >=1.10
+name:               gothic
+version:            0.1.6
+license:            BSD3
+license-file:       LICENSE
+copyright:          (c) 2019-2021 - Michel Boucey
+maintainer:         michel.boucey@gmail.com
+author:             Michel Boucey
+tested-with:        ghc ==8.2.2 || ==8.4.4 || ==8.6.5 || ==8.8.3 || ==8.10.1
+homepage:           https://github.com/MichelBoucey/gothic
+synopsis:           A Haskell Vault KVv2 secret engine client
+description:        A Haskell HashiCorp Vault KVv2 secret engine client library
+category:           DevOps, Security, Database
+build-type:         Simple
+extra-source-files: ReadMe.md
 
-Source-Repository head
-  Type: git
-  Location: https://github.com/MichelBoucey/gothic
+source-repository head
+    type:     git
+    location: https://github.com/MichelBoucey/gothic
 
 library
-  exposed-modules:    Database.Vault.KVv2.Client
-                    , Database.Vault.KVv2.Client.Internal
-                    , Database.Vault.KVv2.Client.Lens
-                    , Database.Vault.KVv2.Client.Requests
-                    , Database.Vault.KVv2.Client.Types
-
-  other-extensions:   OverloadedStrings
-
-  build-depends:      aeson                >= 0.8.0.2 && < 1.6
-                    , base                 >= 4.8.1.0 && < 5
-                    , binary               >= 0.8.5.1 && < 0.9
-                    , connection           >= 0.2.8 && < 0.4
-                    , exceptions           >= 0.10.0 && < 0.11
-                    , hashable             >= 1.2.7.0 && < 1.4
-                    , http-conduit         >= 2.3.2 && < 2.4
-                    , http-client          >= 0.5.13.1 && < 0.8
-                    , http-client-tls      >= 0.3.5.3 && < 0.4
-                    , http-types           >= 0.12.2 && < 0.13
-                    , bytestring           >= 0.10.8.2 && < 0.11
-                    , http-conduit         >= 2.3.2 && < 2.4
-                    , text                 >= 1.2.3.0 && < 1.3
-                    , unordered-containers >= 0.2.9.0 && < 0.3
-                    , lens                 >= 4.16.1 && < 4.20
-                    , lens-aeson           >= 1.0.2 && < 1.2
-                    , scientific           >= 0.3.6.2 && < 0.4
-                    , unix                 >= 2.7.2.2 && < 2.8
-                    , vector               >= 0.12.0.1 && < 0.13
+    exposed-modules:
+        Database.Vault.KVv2.Client
+        Database.Vault.KVv2.Client.Internal
+        Database.Vault.KVv2.Client.Lens
+        Database.Vault.KVv2.Client.Requests
+        Database.Vault.KVv2.Client.Types
 
-  default-language:   Haskell2010
-  GHC-Options:        -Wall
+    default-language: Haskell2010
+    other-extensions: OverloadedStrings
+    ghc-options:      -Wall
+    build-depends:
+        aeson >=0.8.0.2 && <1.6,
+        base >=4.8.1.0 && <5,
+        binary >=0.8.5.1 && <0.9,
+        connection >=0.2.8 && <0.4,
+        exceptions >=0.10.0 && <0.11,
+        hashable >=1.2.7.0 && <1.4,
+        http-conduit >=2.3.2 && <2.4,
+        http-client >=0.5.13.1 && <0.8,
+        http-client-tls >=0.3.5.3 && <0.4,
+        http-types >=0.12.2 && <0.13,
+        bytestring >=0.10.8.2 && <0.11,
+        http-conduit >=2.3.2 && <2.4,
+        text >=1.2.3.0 && <1.3,
+        unordered-containers >=0.2.9.0 && <0.3,
+        lens >=4.16.1 && <5.1,
+        lens-aeson >=1.0.2 && <1.2,
+        scientific >=0.3.6.2 && <0.4,
+        unix >=2.7.2.2 && <2.8,
+        vector >=0.12.0.1 && <0.13
