diff --git a/NXT.cabal b/NXT.cabal
--- a/NXT.cabal
+++ b/NXT.cabal
@@ -1,5 +1,5 @@
 Name:                NXT
-Version:             0.1.5
+Version:             0.1.6
 Synopsis:            A Haskell interface to Lego Mindstorms NXT
 Description:         A Haskell interface to Lego Mindstorms NXT over Bluetoooth. It supports direct commands, messages and
                      many sensors (also unofficial). It has also support for a simple message-based control of a NXT brick
@@ -59,7 +59,7 @@
   HS-source-dirs:      src
   Build-depends:       base >= 4.3 && < 5,
                        mtl >= 1.1 && < 3,
-                       NXT == 0.1.5
+                       NXT == 0.1.6
   GHC-options:         -Wall
 
 Executable nxt-upload
@@ -69,7 +69,7 @@
                        mtl >= 1.1 && < 3,
                        bytestring >= 0.9 && < 1,
                        filepath >= 1.1 && < 2,
-                       NXT == 0.1.5
+                       NXT == 0.1.6
   GHC-options:         -Wall
   GHC-prof-options:    -Wall
   GHC-shared-options:  -Wall
diff --git a/lib/Robotics/NXT/Internals.hs b/lib/Robotics/NXT/Internals.hs
--- a/lib/Robotics/NXT/Internals.hs
+++ b/lib/Robotics/NXT/Internals.hs
@@ -1,9 +1,10 @@
-{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE GeneralizedNewtypeDeriving, DeriveDataTypeable #-}
 
 module Robotics.NXT.Internals where
 
 import Control.Monad.State
 import Data.Time.Clock.POSIX
+import Data.Typeable
 import System.IO
 
 import Robotics.NXT.Externals
@@ -22,10 +23,10 @@
     modules :: [(ModuleName, ModuleInfo)], -- modules info
     sleeptime :: Maybe Duration, -- sleep time limit in seconds
     lastkeepalive :: Maybe POSIXTime -- last time keep alive has been sent
-  }
+  } deriving (Typeable)
 
 instance Show NXTInternals where
-  show _ = "NXTInternals"
+  show = show . typeOf
 
 {-|
 Runs a computation in a context of a given 'NXTInternals' token, returning a value and a new token.
diff --git a/lib/Robotics/NXT/Sensor/Ultrasonic.hs b/lib/Robotics/NXT/Sensor/Ultrasonic.hs
--- a/lib/Robotics/NXT/Sensor/Ultrasonic.hs
+++ b/lib/Robotics/NXT/Sensor/Ultrasonic.hs
@@ -219,7 +219,7 @@
 
 {-|
 Gets last measurement for a given measurement number based on the current mode. To retrieve new 'SingleShot' measurements first
-use 'usSetMode' (with 'SingleShot' as a parameter) to send new ultrasonic ping and after approximately 20ms read the results. (Change
+use 'usSetMode' (with 'SingleShot' as an argument) to send new ultrasonic ping and after approximately 20ms read the results. (Change
 of NXT Bluetooth communication direction takes around 30 ms.) In 'ContinuousMeasurement' mode new measurements are made automatically
 based on the continuous measurement interval value.
 -}