diff --git a/hnix.cabal b/hnix.cabal
index 34cefff..46f0d1e 100644
--- a/hnix.cabal
+++ b/hnix.cabal
@@ -496,7 +496,7 @@ library
     , containers >= 0.5.11.0 && < 0.7
     , contravariant >= 1.5 && < 1.6
     , data-fix >= 0.2.0 && <  0.3
-    , deepseq >=1.4.2 && <1.5
+    , deepseq >=1.4.3 && <1.5
     , dependent-sum >= 0.4 && < 0.5 || >= 0.6.2.0 && < 0.7
     , deriving-compat >=0.3 && <0.6
     , directory >= 1.3.1 && < 1.4
@@ -633,7 +633,7 @@ test-suite hnix-tests
     , bytestring
     , containers
     , data-fix
-    , deepseq >=1.4.2 && <1.5
+    , deepseq >=1.4.3 && <1.5
     , dependent-sum
     , directory
     , exceptions
@@ -692,7 +692,7 @@ benchmark hnix-benchmarks
     , containers
     , criterion
     , data-fix
-    , deepseq >=1.4.2 && <1.5
+    , deepseq >=1.4.3 && <1.5
     , exceptions
     , filepath
     , hashing
diff --git a/src/Nix/Expr/Types.hs b/src/Nix/Expr/Types.hs
index e7c1ed1..4d4c416 100644
--- a/src/Nix/Expr/Types.hs
+++ b/src/Nix/Expr/Types.hs
@@ -127,9 +127,7 @@ data NExprF r
 
 instance Hashable1 NExprF
 
-#if MIN_VERSION_deepseq(1, 4, 3)
 instance NFData1 NExprF
-#endif
 
 #ifdef MIN_VERSION_serialise
 instance Serialise r => Serialise (NExprF r)
@@ -168,9 +166,7 @@ data Binding r
 
 instance Hashable1 Binding
 
-#if MIN_VERSION_deepseq(1, 4, 3)
 instance NFData1 Binding
-#endif
 
 #ifdef MIN_VERSION_serialise
 instance Serialise r => Serialise (Binding r)
@@ -190,9 +186,7 @@ data Params r
 
 instance Hashable1 Params
 
-#if MIN_VERSION_deepseq(1, 4, 3)
 instance NFData1 Params
-#endif
 
 #ifdef MIN_VERSION_serialise
 instance Serialise r => Serialise (Params r)
@@ -219,9 +213,7 @@ instance Hashable2 Antiquoted where
   liftHashWithSalt2 _ hb salt (Antiquoted b) =
     hb (salt `hashWithSalt` (2 :: Int)) b
 
-#if MIN_VERSION_deepseq(1, 4, 3)
 instance NFData v => NFData1 (Antiquoted v)
-#endif
 
 #ifdef MIN_VERSION_serialise
 instance (Serialise v, Serialise r) => Serialise (Antiquoted v r)
@@ -243,9 +235,7 @@ data NString r
 
 instance Hashable1 NString
 
-#if MIN_VERSION_deepseq(1, 4, 3)
 instance NFData1 NString
-#endif
 
 #ifdef MIN_VERSION_serialise
 instance Serialise r => Serialise (NString r)
@@ -304,13 +294,11 @@ instance Generic1 NKeyName where
   from1 = id
   to1   = id
 
-#if MIN_VERSION_deepseq(1, 4, 3)
 instance NFData1 NKeyName where
   liftRnf _ (StaticKey  !_            ) = ()
   liftRnf _ (DynamicKey (Plain !_)    ) = ()
   liftRnf _ (DynamicKey EscapedNewline) = ()
   liftRnf k (DynamicKey (Antiquoted r)) = k r
-#endif
 
 -- | Most key names are just static text, so this instance is convenient.
 instance IsString (NKeyName r) where
@@ -410,10 +398,6 @@ paramName :: Params r -> Maybe VarName
 paramName (Param n       ) = Just n
 paramName (ParamSet _ _ n) = n
 
-#if !MIN_VERSION_deepseq(1, 4, 3)
-instance NFData NExpr
-#endif
-
 $(deriveEq1 ''NExprF)
 $(deriveEq1 ''NString)
 $(deriveEq1 ''Binding)
diff --git a/src/Nix/Expr/Types/Annotated.hs b/src/Nix/Expr/Types/Annotated.hs
index 4ebab38..b1fc4b4 100644
--- a/src/Nix/Expr/Types/Annotated.hs
+++ b/src/Nix/Expr/Types/Annotated.hs
@@ -82,9 +82,7 @@ instance Hashable ann => Hashable1 (Ann ann)
 instance (Serialise ann, Serialise a) => Serialise (Ann ann a)
 #endif
 
-#if MIN_VERSION_deepseq(1, 4, 3)
 instance NFData ann => NFData1 (Ann ann)
-#endif
 
 $(deriveEq1   ''Ann)
 $(deriveEq2   ''Ann)
@@ -110,10 +108,6 @@ type NExprLocF = AnnF SrcSpan NExprF
 -- | A nix expression with source location at each subexpression.
 type NExprLoc = Fix NExprLocF
 
-#if !MIN_VERSION_deepseq(1, 4, 3)
-instance (NFData (f (g a)), NFData (g a)) => NFData (Compose f g a)
-#endif
-
 instance NFData NExprLoc
 
 #ifdef MIN_VERSION_serialise