diff --git a/CHANGELOG.rst b/CHANGELOG.rst
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -6,8 +6,20 @@
 
 .. _PVP: https://pvp.haskell.org/
 
+1.10.0.0 (2020-05-10)
+---------------------
+
+* Git: :tag:`concurrency-1.10.0.0`
+* Hackage: :hackage:`concurrency-1.10.0.0`
+
+Added
+~~~~~
+
+* (:issue:`312`) ``Control.Monad.Conc.Class.getMaskingState``.
+
+
 1.9.0.0 (2020-02-26)
-====================
+--------------------
 
 * Git: :tag:`concurrency-1.9.0.0`
 * Hackage: :hackage:`concurrency-1.9.0.0`
@@ -20,8 +32,9 @@
   * Changed ``newTBQueue`` to accept ``Natural`` as a size.
   * Changed ``lengthTBQueue`` to return a ``Natural``.
 
+
 1.8.1.0 (2019-11-16)
-====================
+--------------------
 
 * Git: :tag:`concurrency-1.8.1.0`
 * Hackage: :hackage:`concurrency-1.8.1.0`
diff --git a/Control/Monad/Conc/Class.hs b/Control/Monad/Conc/Class.hs
--- a/Control/Monad/Conc/Class.hs
+++ b/Control/Monad/Conc/Class.hs
@@ -91,7 +91,8 @@
 
 -- for the class and utilities
 import           Control.Exception            (AsyncException(ThreadKilled),
-                                               Exception, SomeException)
+                                               Exception, MaskingState,
+                                               SomeException)
 import           Control.Monad.Catch          (MonadCatch, MonadMask,
                                                MonadThrow)
 import qualified Control.Monad.Catch          as Ca
@@ -104,6 +105,7 @@
 -- for the 'IO' instance
 import qualified Control.Concurrent           as IO
 import qualified Control.Concurrent.STM.TVar  as IO
+import qualified Control.Exception            as IO
 import qualified Control.Monad.STM            as IO
 import qualified Data.Atomics                 as IO
 import qualified Data.IORef                   as IO
@@ -152,7 +154,7 @@
 -- Do not be put off by the use of @UndecidableInstances@, it is safe
 -- here.
 --
--- @since 1.7.0.0
+-- @since 1.10.0.0
 class ( Monad m
       , MonadCatch m, MonadThrow m, MonadMask m
       , MonadSTM (STM m)
@@ -184,6 +186,7 @@
       , modifyIORefCAS
       , atomically
       , throwTo
+      , getMaskingState
     #-}
 
   -- | The associated 'MonadSTM' for this class.
@@ -496,6 +499,11 @@
   -- @since 1.0.0.0
   throwTo :: Exception e => ThreadId m -> e -> m ()
 
+  -- | Return the 'MaskingState' for the current thread.
+  --
+  -- @since 1.10.0.0
+  getMaskingState :: m MaskingState
+
 -------------------------------------------------------------------------------
 -- Utilities
 
@@ -784,6 +792,7 @@
   atomically          = IO.atomically
   newTVarConc         = IO.newTVarIO
   readTVarConc        = IO.readTVarIO
+  getMaskingState     = IO.getMaskingState
 
 -- | Label the current thread, if the given label is nonempty.
 labelMe :: String -> IO ()
@@ -863,6 +872,7 @@
   atomically          = toIsConc . atomically . fromIsSTM
   newTVarConc         = toIsConc . newTVarConc
   readTVarConc        = toIsConc . readTVarConc
+  getMaskingState     = toIsConc getMaskingState
 
 -------------------------------------------------------------------------------
 -- Transformer instances
@@ -912,7 +922,8 @@
   modifyIORefCAS_ r   = lift . modifyIORefCAS_ r               ; \
   atomically          = lift . atomically                      ; \
   newTVarConc         = lift . newTVarConc                     ; \
-  readTVarConc        = lift . readTVarConc                    }
+  readTVarConc        = lift . readTVarConc                    ; \
+  getMaskingState     = lift getMaskingState                   }
 
 -- | New threads inherit the reader state of their parent, but do not
 -- communicate results back.
diff --git a/concurrency.cabal b/concurrency.cabal
--- a/concurrency.cabal
+++ b/concurrency.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                concurrency
-version:             1.9.0.0
+version:             1.10.0.0
 synopsis:            Typeclasses, functions, and data types for concurrency and STM.
 
 description:
@@ -32,7 +32,7 @@
 source-repository this
   type:     git
   location: https://github.com/barrucadu/dejafu.git
-  tag:      concurrency-1.9.0.0
+  tag:      concurrency-1.10.0.0
 
 library
   exposed-modules:     Control.Monad.Conc.Class