diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,7 @@
 ## 0
 
 * Repository initialized
+
+## 0.1
+
+* Added `runLazyIO` and `runLazyIO_`.
diff --git a/promises.cabal b/promises.cabal
--- a/promises.cabal
+++ b/promises.cabal
@@ -1,6 +1,6 @@
 name:          promises
 category:      Lazy, Concurrent
-version:       0
+version:       0.1
 license:       BSD3
 cabal-version: >= 1.10
 license-file:  LICENSE
diff --git a/src/Data/Promise.hs b/src/Data/Promise.hs
--- a/src/Data/Promise.hs
+++ b/src/Data/Promise.hs
@@ -21,7 +21,11 @@
 -----------------------------------------------------------------------------
 
 module Data.Promise
-  ( Lazy, runLazy, runLazy_
+  ( Lazy
+  , runLazy
+  , runLazy_
+  , runLazyIO
+  , runLazyIO_
   , Promise(..)
   , promise, promise_
   , (!=)
@@ -178,15 +182,21 @@
 -- * Running It All
 --------------------------------------------------------------------------------
 
--- | Run a lazy computation. The final answer is given in the form of a promise to be fulfilled.
--- If the promises is unfulfilled then an user supplied default value will be returned.
-runLazy :: (forall s. Promise s a -> Lazy s b) -> a -> a
-runLazy f d = unsafePerformIO $ do
+runLazyIO :: (forall s. Promise s a -> Lazy s b) -> a -> IO a
+runLazyIO f d = do
   mv <- newEmptyMVar
   v <- newEmptyMVar
   let iv = Promise v (drive d mv v)
   putMVar mv (Just (getLazy (f iv) mv))
   return $ demand iv
+
+runLazyIO_ :: (forall s. Promise s a -> Lazy s b) -> IO a
+runLazyIO_ k = runLazyIO k $ throw BrokenPromise
+
+-- | Run a lazy computation. The final answer is given in the form of a promise to be fulfilled.
+-- If the promises is unfulfilled then an user supplied default value will be returned.
+runLazy :: (forall s. Promise s a -> Lazy s b) -> a -> a
+runLazy f d = unsafePerformIO (runLazyIO f d)
 {-# NOINLINE runLazy #-}
 
 -- | Run a lazy computation. The final answer is given in the form of a promise to be fulfilled.