diff --git a/Haxl/Core/Monad.hs b/Haxl/Core/Monad.hs
index 5745e85..8ea50c4 100644
--- a/Haxl/Core/Monad.hs
+++ b/Haxl/Core/Monad.hs
@@ -56,6 +56,7 @@ import Control.Exception (AllocationLimitExceeded(..))
 import Control.Monad
 import qualified Control.Exception as Exception
 import Control.Applicative hiding (Const)
+import Control.DeepSeq
 import GHC.Exts (IsString(..))
 #if __GLASGOW_HASKELL__ < 706
 import Prelude hiding (catch)
@@ -526,7 +527,7 @@ performFetches n env reqs = do
   let roundtime = realToFrac (diffUTCTime t1 t0) :: Double
 
   ifReport f 1 $
-    modifyIORef' sref $ \(Stats rounds) ->
+    modifyIORef' sref $ \(Stats rounds) -> roundstats `deepseq`
       Stats (RoundStats (microsecs roundtime) dsroundstats: rounds)
 
   ifTrace f 1 $
diff --git a/haxl.cabal b/haxl.cabal
index 73db83c..89983cc 100644
--- a/haxl.cabal
+++ b/haxl.cabal
@@ -31,6 +31,7 @@ library
     base == 4.*,
     bytestring >= 0.9 && < 0.11,
     containers == 0.5.*,
+    deepseq,
     directory >= 1.1 && < 1.3,
     filepath >= 1.3 && < 1.5,
     hashable == 1.2.*,