diff --git a/initial-encoding/src/Parser/Initial.hs b/initial-encoding/src/Parser/Initial.hs
index 0be55a5..c39fc76 100644
--- a/initial-encoding/src/Parser/Initial.hs
+++ b/initial-encoding/src/Parser/Initial.hs
@@ -119,6 +119,10 @@ parseSingle = expr >>= either (fail . unpack) pure
 -- Strict
 -- ========================================
 
+instance NFData Result where
+  rnf (RInt e) = e `seq` ()
+  rnf (RBool e) = e `seq` ()
+
 parseStrict :: Parser Result
 parseStrict = term >>= expr
  where
@@ -144,7 +148,7 @@ parseStrict = term >>= expr
       lhs <- cast t
       rhs <- cast t'
       toResult $ bin (f lhs) (f rhs)
-    a `seq` expr a
+    a `deepseq` expr a
 
   term = do
     p <- M.option Nothing $ Just <$> symbol "("
diff --git a/tagless-final/src/Parser/Final.hs b/tagless-final/src/Parser/Final.hs
index 041c29a..280efa6 100644
--- a/tagless-final/src/Parser/Final.hs
+++ b/tagless-final/src/Parser/Final.hs
@@ -130,9 +130,9 @@ binDyn bin lhs rhs = do
   pure . Dynamic type' $ bin lhs' rhs'
 
 parseSingle :: forall repr. Symantics repr => Parser (Dynamic repr)
-parseSingle = expr >>= \case
-  Left (offset, msg) -> M.setOffset offset >> fail msg
-  Right a -> pure a
+parseSingle =
+  let ferr (offset, msg) = M.setOffset offset >> fail msg
+   in expr >>= either ferr pure
  where
   expr = E.makeExprParser term
     [ [binary "+" eAdd, binary "-" eSub]