diff --git a/Test/Tasty/Bench.hs b/Test/Tasty/Bench.hs
--- a/Test/Tasty/Bench.hs
+++ b/Test/Tasty/Bench.hs
@@ -788,7 +788,7 @@
 --
 -- Drop-in replacement for 'Criterion.whnfIO' and 'Gauge.whnfIO'.
 --
-whnfIO :: NFData a => IO a -> Benchmarkable
+whnfIO :: IO a -> Benchmarkable
 whnfIO = ioToBench id
 {-# INLINE whnfIO #-}
 
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,7 @@
+# 0.2.2
+
+* Remove `NFData` constraint from `whnfIO`.
+
 # 0.2.1
 
 * Fix integer overflow in stdev computations.
diff --git a/tasty-bench.cabal b/tasty-bench.cabal
--- a/tasty-bench.cabal
+++ b/tasty-bench.cabal
@@ -1,5 +1,5 @@
 name:          tasty-bench
-version:       0.2.1
+version:       0.2.2
 cabal-version: >=1.10
 build-type:    Simple
 license:       MIT