diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0ced94b..42e2dcd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+## [0.2.1.1] - 2023-08-21
+### Added
+- `NEO4J_BOLT_VERSION` configuration.
+
 ## [0.2.1.0] - 2021-04-24
 ### Changed
 - Added `HasCallStack` to unsafe functions;
diff --git a/bcd-config.cabal b/bcd-config.cabal
index aaa3832..2ce0c4f 100644
--- a/bcd-config.cabal
+++ b/bcd-config.cabal
@@ -1,5 +1,5 @@
 name:           bcd-config
-version:        0.2.1.0
+version:        0.2.1.1
 synopsis:       Library to get config.
 description:    Library to get config to different systems
 homepage:       https://github.com/biocad/bcd-config#readme
diff --git a/src/System/BCD/Config.hs b/src/System/BCD/Config.hs
index 776468f..41ba58c 100644
--- a/src/System/BCD/Config.hs
+++ b/src/System/BCD/Config.hs
@@ -41,12 +41,19 @@ loadDotenv = liftIO $ void $ loadFile defaultConfig
 class Typeable a => GetEnv a where
   getEnv :: (HasCallStack, MonadIO m) => String -> m a
   getEnv key = do
-      valueM <- liftIO $ lookupEnv key
+      valueM <- getEnvMaybe key
       case valueM of
         Nothing -> error $ "bcd-config: could not find environment <" <> key <> ">"
+        Just val -> return val
+
+  getEnvMaybe :: (HasCallStack, MonadIO m) => String -> m (Maybe a)
+  getEnvMaybe key = do
+      valueM <- liftIO $ lookupEnv key
+      case valueM of
+        Nothing -> return Nothing
         Just val -> case convertSafe val of
           Nothing -> error $ "bcd-config: could not parse environment <" <> key <> "> = <" <> val <> ">" <> " as type " <> show (typeRep @a)
-          Just a -> return a
+          Just a -> return $ Just a
 
   convert :: HasCallStack => String -> a
   convert = fromJust . convertSafe
diff --git a/src/System/BCD/Config/Neo4j.hs b/src/System/BCD/Config/Neo4j.hs
index 80dc708..2945579 100644
--- a/src/System/BCD/Config/Neo4j.hs
+++ b/src/System/BCD/Config/Neo4j.hs
@@ -12,6 +12,7 @@ module System.BCD.Config.Neo4j
   , timeout
   , rps
   , descr
+  , version
   ) where
 
 import           Control.DeepSeq   (NFData)
@@ -33,6 +34,7 @@ data Neo4jConfig = Neo4jConfig { _host     :: String
                                , _timeout  :: Int
                                , _rps      :: Int
                                , _descr    :: String
+                               , _version  :: Maybe Int
                                }
   deriving (Show, Read, Eq, Generic)
 
@@ -61,4 +63,5 @@ instance FromDotenv Neo4jConfig where
       _timeout  <- getEnv "NEO4J_TIMEOUT"
       _rps      <- getEnv "NEO4J_RPS"
       _descr    <- getEnv "NEO4J_DESCR"
+      _version  <- getEnvMaybe "NEO4J_BOLT_VERSION"
       pure Neo4jConfig{..}