diff --git a/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Util/CBOR.hs b/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Util/CBOR.hs
index 1ecdc42d10..d90c0991cd 100644
--- a/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Util/CBOR.hs
+++ b/ouroboros-consensus/src/ouroboros-consensus/Ouroboros/Consensus/Util/CBOR.hs
@@ -197,11 +197,11 @@ readIncremental = \(SomeHasFS hasFS) decoder fp -> do
        -> CRC
        -> CBOR.R.IDecode (U.PrimState m) a
        -> m (Either ReadIncrementalErr (a, CRC))
-    go hasFS@HasFS{..} h checksum  (CBOR.R.Partial k) = do
+    go hasFS@HasFS{..} h !checksum  (CBOR.R.Partial k) = do
         bs   <- hGetSome h (fromIntegral defaultChunkSize)
         dec' <- U.stToIO $ k (checkEmpty bs)
         go hasFS h (updateCRC bs checksum) dec'
-    go _ _ checksum (CBOR.R.Done leftover _ a) =
+    go _ _ !checksum (CBOR.R.Done leftover _ a) =
         return $ if BS.null leftover
                    then Right (a, checksum)
                    else Left $ TrailingBytes leftover