diff --git a/src/System/Logger.hs b/src/System/Logger.hs
index 956b0af6ee6b5a566e65b8b08ca9b77d267cc20e..4bd58603397eab16ddab4d93b1e82e83b320f940 100644
--- a/src/System/Logger.hs
+++ b/src/System/Logger.hs
@@ -85,12 +85,16 @@ data Logger = Logger
 -- Please note that the 'logLevel' can be dynamically adjusted by setting
 -- the environment variable @LOG_LEVEL@ accordingly. Likewise the buffer
 -- size can be dynamically set via @LOG_BUFFER@ and netstrings encoding
--- can be enabled with @LOG_NETSTR=True@
+-- can be enabled with @LOG_NETSTR=True@.  **NOTE: If you do this any custom
+-- renderers you may have passed with the settings will be overwritten!**
 --
 -- Since version 0.11 one can also use @LOG_LEVEL_MAP@ to specify log
 -- levels per (named) logger. The syntax uses standard haskell syntax for
 -- association lists of type @[(Text, Level)]@. For example:
 --
+-- If you want to ignore environment variables, call @setReadEnvironment False@ on the
+-- 'Settings'.
+--
 -- @
 -- $ LOG_LEVEL=Info LOG_LEVEL_MAP='[("foo", Warn), ("bar", Trace)]' cabal repl
 -- > g1 <- new defSettings
@@ -108,10 +112,10 @@ data Logger = Logger
 -- @
 new :: MonadIO m => Settings -> m Logger
 new s = liftIO $ do
-    !n <- fmap (readNote "Invalid LOG_BUFFER") <$> lookupEnv "LOG_BUFFER"
-    !l <- fmap (readNote "Invalid LOG_LEVEL")  <$> lookupEnv "LOG_LEVEL"
-    !e <- fmap (readNote "Invalid LOG_NETSTR") <$> lookupEnv "LOG_NETSTR"
-    !m <- fromMaybe "[]" <$> lookupEnv "LOG_LEVEL_MAP"
+    !n <- fmap (readNote "Invalid LOG_BUFFER") <$> maybeLookupEnv "LOG_BUFFER"
+    !l <- fmap (readNote "Invalid LOG_LEVEL")  <$> maybeLookupEnv "LOG_LEVEL"
+    !e <- fmap (readNote "Invalid LOG_NETSTR") <$> maybeLookupEnv "LOG_NETSTR"
+    !m <- fromMaybe "[]" <$> maybeLookupEnv "LOG_LEVEL_MAP"
     let !k  = logLevelMap s `mergeWith` m
     let !s' = setLogLevel (fromMaybe (logLevel s) l)
             . maybe id (bool id setRendererNetstr) e
@@ -120,6 +124,12 @@ new s = liftIO $ do
     g <- fn (output s) (fromMaybe (bufSize s) n)
     Logger g s' <$> mkGetDate (format s)
   where
+    maybeLookupEnv :: String -> IO (Maybe String)
+    maybeLookupEnv key =
+        if readEnvironment s
+            then lookupEnv key
+            else pure Nothing
+
     fn StdOut   = FL.newStdoutLoggerSet
     fn StdErr   = FL.newStderrLoggerSet
     fn (Path p) = flip FL.newFileLoggerSet p
@@ -141,7 +151,7 @@ readNote m s = case reads s of
 -- | Logs a message with the given level if greater or equal to the
 -- logger's threshold.
 log :: MonadIO m => Logger -> Level -> (Msg -> Msg) -> m ()
-log g l m = unless (level g > l) . liftIO $ putMsg g l m
+log g l m = unless (level g > l) $ putMsg g l m
 {-# INLINE log #-}
 
 -- | Abbreviation of 'log' using the corresponding log level.
diff --git a/src/System/Logger/Settings.hs b/src/System/Logger/Settings.hs
index d801840de7d0b419b2ece94c733aef0ab35c7762..1652c664d2e3e5acfe46ff864225def62439b443 100644
--- a/src/System/Logger/Settings.hs
+++ b/src/System/Logger/Settings.hs
@@ -34,6 +34,8 @@ module System.Logger.Settings
     , nameMsg
     , renderer
     , setRenderer
+    , readEnvironment
+    , setReadEnvironment
     , iso8601UTC
     ) where
 
@@ -49,15 +51,16 @@ import System.Logger.Message
 import qualified Data.ByteString.Lazy.Builder as B
 
 data Settings = Settings
-    { _logLevel   :: !Level              -- ^ messages below this log level will be suppressed
-    , _levelMap   :: !(Map Text Level)   -- ^ log level per named logger
-    , _output     :: !Output             -- ^ log sink
-    , _format     :: !(Maybe DateFormat) -- ^ the timestamp format (use 'Nothing' to disable timestamps)
-    , _delimiter  :: !ByteString         -- ^ text to intersperse between fields of a log line
-    , _bufSize    :: !Int                -- ^ how many bytes to buffer before commiting to sink
-    , _name       :: !(Maybe Text)       -- ^ logger name
-    , _nameMsg    :: !(Msg -> Msg)
-    , _renderer   :: !Renderer
+    { _logLevel        :: !Level              -- ^ messages below this log level will be suppressed
+    , _levelMap        :: !(Map Text Level)   -- ^ log level per named logger
+    , _output          :: !Output             -- ^ log sink
+    , _format          :: !(Maybe DateFormat) -- ^ the timestamp format (use 'Nothing' to disable timestamps)
+    , _delimiter       :: !ByteString         -- ^ text to intersperse between fields of a log line
+    , _bufSize         :: !Int                -- ^ how many bytes to buffer before commiting to sink
+    , _name            :: !(Maybe Text)       -- ^ logger name
+    , _nameMsg         :: !(Msg -> Msg)
+    , _renderer        :: !Renderer
+    , _readEnvironment :: !Bool               -- ^ should 'new' check @LOG_*@ process environment settings?
     }
 
 output :: Settings -> Output
@@ -147,6 +150,12 @@ renderer = _renderer
 setRenderer :: Renderer -> Settings -> Settings
 setRenderer f s = s { _renderer = f }
 
+readEnvironment :: Settings -> Bool
+readEnvironment = _readEnvironment
+
+setReadEnvironment :: Bool -> Settings -> Settings
+setReadEnvironment f s = s { _readEnvironment = f }
+
 data Level
     = Trace
     | Debug
@@ -179,19 +188,21 @@ type Renderer = ByteString -> DateFormat -> Level -> [Element] -> B.Builder
 
 -- | Default settings:
 --
---   * 'logLevel'   = 'Debug'
+--   * 'logLevel'        = 'Debug'
+--
+--   * 'output'          = 'StdOut'
 --
---   * 'output'     = 'StdOut'
+--   * 'format'          = 'iso8601UTC'
 --
---   * 'format'     = 'iso8601UTC'
+--   * 'delimiter'       = \", \"
 --
---   * 'delimiter'  = \", \"
+--   * 'netstrings'      = False
 --
---   * 'netstrings' = False
+--   * 'bufSize'         = 'FL.defaultBufSize'
 --
---   * 'bufSize'    = 'FL.defaultBufSize'
+--   * 'name'            = Nothing
 --
---   * 'name'       = Nothing
+--   * 'readEnvironment' = True
 --
 defSettings :: Settings
 defSettings = Settings
@@ -204,3 +215,4 @@ defSettings = Settings
     Nothing
     id
     (\s _ _ -> renderDefault s)
+    True