diff --git a/global-variables.cabal b/global-variables.cabal
--- a/global-variables.cabal
+++ b/global-variables.cabal
@@ -1,5 +1,5 @@
 Name:               global-variables
-Version:            1.0
+Version:            1.0.1.0
 
 Synopsis:           Namespaced, global, and top-level mutable variables without
                     unsafePerformIO.
@@ -33,6 +33,12 @@
    extends their handling significantly.
    .
    Examples are in the documentation of "Data.Global".
+   .
+   Version History:
+   .
+   1.0.1.0: added declareEmptyMVar and widened the stm dependency
+   .
+   1.0: First public release
 
 License:            BSD3
 License-file:       LICENSE
@@ -46,6 +52,7 @@
 
 Build-type:         Simple
 
+Tested-With:        GHC == 7.0.4, GHC == 7.2.2
 -- Extra files to be distributed with the package, such as examples or
 -- a README.
 -- Extra-source-files:
@@ -58,7 +65,7 @@
 
   Build-depends:      base >= 4 && < 5
                     , containers >= 0.3 && < 0.5
-                    , stm >= 2.1 && < 2.2
+                    , stm >= 2.1 && < 2.3
 
   Other-modules:    Data.Global.Registry
 
diff --git a/src/Data/Global.hs b/src/Data/Global.hs
--- a/src/Data/Global.hs
+++ b/src/Data/Global.hs
@@ -46,6 +46,7 @@
   -- * Reference of Variable Declaration Functions
     declareIORef
   , declareMVar
+  , declareEmptyMVar
   , declareTVar
 
 ) where
diff --git a/src/Data/Global/Registry.hs b/src/Data/Global/Registry.hs
--- a/src/Data/Global/Registry.hs
+++ b/src/Data/Global/Registry.hs
@@ -13,24 +13,27 @@
 -----------------------------------------------------------------------------------------------
 module Data.Global.Registry (
   -- * Public Interface
-    declareIORef, declareMVar, declareTVar
+    declareIORef, declareMVar, declareEmptyMVar, declareTVar
 
   -- * Private Testing Interface
   , lookupOrInsert
   , setupRegistry
 ) where
 
+import Control.Concurrent.MVar ( MVar, newMVar, newEmptyMVar, modifyMVar )
 #if __GLASGOW_HASKELL__ < 702
+import Control.Concurrent.MVar ( takeMVar, putMVar )
+#endif
+import Control.Concurrent.STM  ( TVar, newTVarIO )
+#if __GLASGOW_HASKELL__ < 702
 import Control.Exception       ( evaluate )
 #endif
-import Control.Concurrent.MVar
-import Control.Concurrent.STM
 import Data.IORef
 import Data.Dynamic
 import Data.Map as M
-import GHC.Conc (pseq)
+import GHC.Conc                ( pseq )
+import GHC.IO                  ( unsafePerformIO, unsafeDupablePerformIO )
 
-import System.IO.Unsafe
 
 
 #if __GLASGOW_HASKELL__ >= 702
@@ -39,6 +42,8 @@
 type Registry = Map (Int,Int,String) Dynamic
 #endif
 
+
+
 -- | Test helper
 setupRegistry :: IO (MVar Registry)
 setupRegistry = m `pseq` newMVar m
@@ -64,8 +69,8 @@
     -> String
     -> a
     -> IO (ref a)
-lookupOrInsert registry new name val
-    | registry `pseq` new `pseq` name `pseq` val `pseq` False = undefined
+lookupOrInsert registry new name _
+    | registry `pseq` new `pseq` name `pseq` False = undefined
 lookupOrInsert registry new name val = modifyMVar registry lkup
   where
     err ex got = error $ "Data.Global.Registry: Invariant violation\n"
@@ -140,6 +145,18 @@
 
 
 
+lookupOrInsertEmptyMVar
+    :: forall a. Typeable a
+    => String
+    -> IO (MVar a)
+lookupOrInsertEmptyMVar name = lookupOrInsert globalRegistry newEmptyMVar' name (undefined :: a)
+  where
+    newEmptyMVar' :: a -> IO (MVar a)
+    newEmptyMVar' _ = newEmptyMVar
+{-# NOINLINE lookupOrInsertEmptyMVar #-}
+
+
+
 lookupOrInsertTVar
     :: Typeable a
     => String
@@ -161,11 +178,11 @@
 -- pragma in order to define top-level 'IORef's.
 declareIORef
     :: Typeable a
-    => String     -- ^ The identifying name
-    -> a          -- ^ The initial value of the 'IORef', it may or may not be used.
-    -> (IORef a)  -- ^ A unique 'IORef' determined by @(name, typeOf val)@. Whether it refers
-                  -- to the given initial value or not is unspecified.
-declareIORef name val = unsafePerformIO $ lookupOrInsertIORef name val
+    => String   -- ^ The identifying name
+    -> a        -- ^ The initial value of the 'IORef', it may or may not be used.
+    -> IORef a  -- ^ A unique 'IORef' determined by @(name, typeOf val)@. Whether it refers to
+                -- the given initial value or not is unspecified.
+declareIORef name val = unsafeDupablePerformIO $ lookupOrInsertIORef name val
 {-# NOINLINE declareIORef #-}
 
 
@@ -182,15 +199,33 @@
 -- pragma in order to define top-level 'MVar's.
 declareMVar
     :: Typeable a
-    => String    -- ^ The identifying name
-    -> a         -- ^ The initial value of the 'MVar', it may or may not be used.
-    -> (MVar a)  -- ^ A unique 'MVar' determined by @(name, typeOf val)@. Whether it refers to
-                 -- the given initial value or not is unspecified.
-declareMVar name val = unsafePerformIO $ lookupOrInsertMVar name val
+    => String  -- ^ The identifying name
+    -> a       -- ^ The initial value of the 'MVar', it may or may not be used.
+    -> MVar a  -- ^ A unique 'MVar' determined by @(name, typeOf val)@. Whether it refers to
+               -- the given initial value or not is unspecified.
+declareMVar name val = unsafeDupablePerformIO $ lookupOrInsertMVar name val
 {-# NOINLINE declareMVar #-}
 
 
+-- | @declareEmptyMVar name@ maps a variable name to an 'MVar'. Calling it multiple times with
+-- the same @name@ and type of the expected 'MVar' will always return the same 'MVar'.
+--
+-- @
+-- someVar :: MVar Int
+-- someVar = declareEmptyMVar \"my-global-some-var\"
+-- @
+--
+-- Note, there is /no/ need to use 'unsafePerformIO' or to add a @{-\# NOINLINE someVar \#-}@
+-- pragma in order to define top-level 'MVar's.
+declareEmptyMVar
+    :: Typeable a
+    => String  -- ^ The identifying name
+    -> MVar a  -- ^ A unique 'MVar' determined by @(name, typeOf val)@. Whether it is still
+               -- empty depends on the rest of the program.
+declareEmptyMVar name = unsafeDupablePerformIO $ lookupOrInsertEmptyMVar name
+{-# NOINLINE declareEmptyMVar #-}
 
+
 -- | @declareTVar name val@ maps a variable name to an 'TVar'. Calling it multiple times with the same
 -- @name@ and type of 'val' will always return the same 'TVar'.
 --
@@ -203,9 +238,9 @@
 -- pragma in order to define top-level 'TVar's.
 declareTVar
     :: Typeable a
-    => String    -- ^ The identifying name
-    -> a         -- ^ The initial value of the 'TVar', it may or may not be used.
-    -> (TVar a)  -- ^ A unique 'TVar' determined by @(name, typeOf val)@. Whether it refers to
-                 -- the given initial value or not is unspecified.
-declareTVar name val = unsafePerformIO $ lookupOrInsertTVar name val
+    => String  -- ^ The identifying name
+    -> a       -- ^ The initial value of the 'TVar', it may or may not be used.
+    -> TVar a  -- ^ A unique 'TVar' determined by @(name, typeOf val)@. Whether it refers to
+               -- the given initial value or not is unspecified.
+declareTVar name val = unsafeDupablePerformIO $ lookupOrInsertTVar name val
 {-# NOINLINE declareTVar #-}