diff --git a/Control/Concurrent/Chan/Strict.hs b/Control/Concurrent/Chan/Strict.hs
--- a/Control/Concurrent/Chan/Strict.hs
+++ b/Control/Concurrent/Chan/Strict.hs
@@ -41,7 +41,7 @@
 
 import System.IO.Unsafe         ( unsafeInterleaveIO )
 import Control.Concurrent.MVar.Strict
-import Control.Parallel.Strategies
+import Control.DeepSeq
 
 -- A channel is represented by two @MVar@s keeping track of the two ends
 -- of the channel contents,i.e.,  the read- and write ends. Empty @MVar@s
diff --git a/Control/Concurrent/MVar/Strict.hs b/Control/Concurrent/MVar/Strict.hs
--- a/Control/Concurrent/MVar/Strict.hs
+++ b/Control/Concurrent/MVar/Strict.hs
@@ -45,6 +45,7 @@
 import Prelude
 import Control.OldException as Exception
 import Control.Parallel.Strategies
+import Control.DeepSeq
 
 -- |Put a value into an 'MVar'.  If the 'MVar' is currently full,
 -- 'putMVar' will wait until it becomes empty.
diff --git a/strict-concurrency.cabal b/strict-concurrency.cabal
--- a/strict-concurrency.cabal
+++ b/strict-concurrency.cabal
@@ -1,5 +1,5 @@
 Name:           strict-concurrency
-Version:        0.2.3
+Version:        0.2.4
 Synopsis:       Strict concurrency abstractions
 Category:       Control
 Description:
@@ -13,9 +13,9 @@
 License-File:   LICENSE
 Author:         Don Stewart <dons@galois.com>
 Maintainer:     Don Stewart <dons@galois.com>
-Copyright:      (c) 2007-8 Don Stewart
+Copyright:      (c) 2007-10 Don Stewart
 Homepage:       http://code.haskell.org/~dons/code/strict-concurrency
-build-depends:  base >= 3 && < 5, parallel
+build-depends:  base >= 4 && < 5, parallel >= 3, deepseq >= 1
 ghc-options:    -Wall -fglasgow-exts
 extensions:     CPP, BangPatterns
 build-type:     Simple