diff --git a/exe/GarnetRs/Wrapped.hs b/exe/GarnetRs/Wrapped.hs
index ee80ce0..e98a2c0 100644
--- a/exe/GarnetRs/Wrapped.hs
+++ b/exe/GarnetRs/Wrapped.hs
@@ -29,8 +29,8 @@ data Shape
     | Rectangle CDouble CDouble
 convertShape :: Shape -> Raw.Shape
 convertShape = \case
-    Circle r -> Raw.Shape (Raw.Shape_Tag 0) $ Raw.set_shape_body_circle $ Raw.Circle_Body r
-    Rectangle w h -> Raw.Shape (Raw.Shape_Tag 1) $ Raw.set_shape_body_rectangle $ Raw.Rectangle_Body w h
+    Circle r -> Raw.Shape Raw.Circle $ Raw.set_shape_body_circle $ Raw.Circle_Body r
+    Rectangle w h -> Raw.Shape Raw.Rectangle $ Raw.set_shape_body_rectangle $ Raw.Rectangle_Body w h
 
 hello :: ByteString -> IO ()
 hello s = useAsCString s $ Raw.hello . unsafeFromPtr
diff --git a/generate-bindings b/generate-bindings
index 10e240b..0e1ba05 100755
--- a/generate-bindings
+++ b/generate-bindings
@@ -36,56 +36,11 @@ echo "  Raw header written to $HEADER"
 
 # --- Step 3: Patch the header for hs-bindgen compatibility ---
 #
-# Two patches are needed, both due to hs-bindgen limitations with cbindgen's
-# output for #[repr(C, u8)] tagged enums:
-#
-# 1. cbindgen emits:    enum Shape_Tag { Circle, Rectangle, };
-#                       typedef uint8_t Shape_Tag;
-#    hs-bindgen needs:  typedef uint8_t Shape_Tag;
-#                       #define Circle 0
-#                       #define Rectangle 1
-#    See: no upstream issue yet for hs-bindgen
-#
-# 2. cbindgen emits:    union { ... };       (anonymous)
-#    hs-bindgen needs:  union { ... } body;  (named)
-#    See: https://github.com/well-typed/hs-bindgen/issues/1649
+# cbindgen emits:    union { ... };       (anonymous)
+# hs-bindgen needs:  union { ... } body;  (named)
+# See: https://github.com/well-typed/hs-bindgen/issues/1649
 echo "=== Patching header ==="
 awk '
-# State machine for enum->typedef+define transformation
-/^enum [A-Za-z_][A-Za-z0-9_]* \{$/ {
-    in_enum = 1
-    enum_name = $2
-    variant_count = 0
-    delete variants
-    next
-}
-in_enum && /^\};$/ {
-    # Next line should be: typedef <type> <enum_name>;
-    in_enum = 0
-    pending_enum = 1
-    next
-}
-in_enum {
-    # Collect variant names (strip trailing comma and whitespace)
-    v = $0
-    gsub(/^[[:space:]]+/, "", v)
-    gsub(/,[[:space:]]*$/, "", v)
-    if (v != "") {
-        variants[variant_count] = v
-        variant_count++
-    }
-    next
-}
-pending_enum && /^typedef [A-Za-z0-9_]+ / {
-    # Emit: typedef <type> <name>; then #define for each variant
-    print $0
-    for (i = 0; i < variant_count; i++) {
-        printf "#define %s  %d\n", variants[i], i
-    }
-    pending_enum = 0
-    next
-}
-
 # Name anonymous unions: }; at end of union block inside struct -> } body;
 /^  \};$/ && saw_union {
     print "  } body;"
diff --git a/generated/GarnetRs.hs b/generated/GarnetRs.hs
index 07ba5b8..dd7470d 100644
--- a/generated/GarnetRs.hs
+++ b/generated/GarnetRs.hs
@@ -3,12 +3,12 @@
 {-# LANGUAGE DerivingStrategies #-}
 {-# LANGUAGE DerivingVia #-}
 {-# LANGUAGE DuplicateRecordFields #-}
-{-# LANGUAGE ExplicitForAll #-}
 {-# LANGUAGE FlexibleContexts #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MagicHash #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE NoImplicitPrelude #-}
+{-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE TypeApplications #-}
 {-# LANGUAGE TypeFamilies #-}
@@ -19,8 +19,7 @@
 module GarnetRs where
 
 import qualified Data.Array.Byte
-import qualified Data.Bits as Bits
-import qualified Data.Ix as Ix
+import qualified Data.List.NonEmpty
 import qualified Data.Primitive.Types
 import qualified Data.Proxy
 import qualified Foreign as F
@@ -28,16 +27,16 @@ import qualified Foreign.C as FC
 import qualified GHC.Generics
 import qualified GHC.Ptr as Ptr
 import qualified GHC.Records
+import qualified HsBindgen.Runtime.CEnum
 import qualified HsBindgen.Runtime.HasCField
-import qualified HsBindgen.Runtime.Internal.Bitfield
 import qualified HsBindgen.Runtime.Internal.ByteArray
 import qualified HsBindgen.Runtime.Internal.HasFFIType
 import qualified HsBindgen.Runtime.Internal.SizedByteArray
 import qualified HsBindgen.Runtime.LibC
 import qualified HsBindgen.Runtime.Marshal
-import Data.Bits (FiniteBits)
+import qualified Text.Read
 import HsBindgen.Runtime.Internal.TypeEquality (TyEq)
-import Prelude ((<*>), (>>), Bounded, Enum, Eq, Int, Integral, Num, Ord, Read, Real, Show, pure)
+import Prelude ((<*>), (>>), Eq, Int, Ord, Read, Show, pure, showsPrec)
 
 {-| __C declaration:__ @struct T@
 
@@ -114,34 +113,86 @@ instance ( TyEq ty ((HsBindgen.Runtime.HasCField.CFieldType T) "b")
   getField =
     HsBindgen.Runtime.HasCField.fromPtr (Data.Proxy.Proxy @"b")
 
-{-| __C declaration:__ @Shape_Tag@
+{-| __C declaration:__ @enum Shape_Tag@
 
-    __defined at:__ @garnet_rs.h 11:17@
+    __defined at:__ @garnet_rs.h 11:14@
 
     __exported by:__ @garnet_rs.h@
 -}
 newtype Shape_Tag = Shape_Tag
-  { unwrap :: HsBindgen.Runtime.LibC.Word8
+  { unwrap :: FC.CUInt
   }
   deriving stock (GHC.Generics.Generic)
-  deriving stock (Eq, Ord, Read, Show)
-  deriving newtype
-    ( HsBindgen.Runtime.Marshal.StaticSize
-    , HsBindgen.Runtime.Marshal.ReadRaw
-    , HsBindgen.Runtime.Marshal.WriteRaw
-    , F.Storable
-    , HsBindgen.Runtime.Internal.HasFFIType.HasFFIType
-    , Data.Primitive.Types.Prim
-    , HsBindgen.Runtime.Internal.Bitfield.Bitfield
-    , Bits.Bits
-    , Bounded
-    , Enum
-    , FiniteBits
-    , Integral
-    , Ix.Ix
-    , Num
-    , Real
-    )
+  deriving stock (Eq, Ord)
+  deriving newtype (HsBindgen.Runtime.Internal.HasFFIType.HasFFIType)
+
+instance HsBindgen.Runtime.Marshal.StaticSize Shape_Tag where
+
+  staticSizeOf = \_ -> (4 :: Int)
+
+  staticAlignment = \_ -> (4 :: Int)
+
+instance HsBindgen.Runtime.Marshal.ReadRaw Shape_Tag where
+
+  readRaw =
+    \ptr0 ->
+          pure Shape_Tag
+      <*> HsBindgen.Runtime.Marshal.readRawByteOff ptr0 (0 :: Int)
+
+instance HsBindgen.Runtime.Marshal.WriteRaw Shape_Tag where
+
+  writeRaw =
+    \ptr0 ->
+      \s1 ->
+        case s1 of
+          Shape_Tag unwrap2 ->
+            HsBindgen.Runtime.Marshal.writeRawByteOff ptr0 (0 :: Int) unwrap2
+
+deriving via HsBindgen.Runtime.Marshal.EquivStorable Shape_Tag instance F.Storable Shape_Tag
+
+deriving via FC.CUInt instance Data.Primitive.Types.Prim Shape_Tag
+
+instance HsBindgen.Runtime.CEnum.CEnum Shape_Tag where
+
+  type CEnumZ Shape_Tag = FC.CUInt
+
+  toCEnum = Shape_Tag
+
+  fromCEnum = GHC.Records.getField @"unwrap"
+
+  declaredValues =
+    \_ ->
+      HsBindgen.Runtime.CEnum.declaredValuesFromList [ (0, Data.List.NonEmpty.singleton "Circle")
+                                                     , (1, Data.List.NonEmpty.singleton "Rectangle")
+                                                     ]
+
+  showsUndeclared =
+    HsBindgen.Runtime.CEnum.showsWrappedUndeclared "Shape_Tag"
+
+  readPrecUndeclared =
+    HsBindgen.Runtime.CEnum.readPrecWrappedUndeclared "Shape_Tag"
+
+  isDeclared = HsBindgen.Runtime.CEnum.seqIsDeclared
+
+  mkDeclared = HsBindgen.Runtime.CEnum.seqMkDeclared
+
+instance HsBindgen.Runtime.CEnum.SequentialCEnum Shape_Tag where
+
+  minDeclaredValue = Circle
+
+  maxDeclaredValue = Rectangle
+
+instance Show Shape_Tag where
+
+  showsPrec = HsBindgen.Runtime.CEnum.shows
+
+instance Read Shape_Tag where
+
+  readPrec = HsBindgen.Runtime.CEnum.readPrec
+
+  readList = Text.Read.readListDefault
+
+  readListPrec = Text.Read.readListPrecDefault
 
 instance ( TyEq ty ((HsBindgen.Runtime.HasCField.CFieldType Shape_Tag) "unwrap")
          ) => GHC.Records.HasField "unwrap" (Ptr.Ptr Shape_Tag) (Ptr.Ptr ty) where
@@ -151,32 +202,31 @@ instance ( TyEq ty ((HsBindgen.Runtime.HasCField.CFieldType Shape_Tag) "unwrap")
 
 instance HsBindgen.Runtime.HasCField.HasCField Shape_Tag "unwrap" where
 
-  type CFieldType Shape_Tag "unwrap" =
-    HsBindgen.Runtime.LibC.Word8
+  type CFieldType Shape_Tag "unwrap" = FC.CUInt
 
   offset# = \_ -> \_ -> 0
 
 {-| __C declaration:__ @Circle@
 
-    __defined at:__ @garnet_rs.h 12:9@
+    __defined at:__ @garnet_rs.h 12:3@
 
     __exported by:__ @garnet_rs.h@
 -}
-circle :: FC.CInt
-circle = (0 :: FC.CInt)
+pattern Circle :: Shape_Tag
+pattern Circle = Shape_Tag 0
 
 {-| __C declaration:__ @Rectangle@
 
-    __defined at:__ @garnet_rs.h 13:9@
+    __defined at:__ @garnet_rs.h 13:3@
 
     __exported by:__ @garnet_rs.h@
 -}
-rectangle :: FC.CInt
-rectangle = (1 :: FC.CInt)
+pattern Rectangle :: Shape_Tag
+pattern Rectangle = Shape_Tag 1
 
 {-| __C declaration:__ @struct Circle_Body@
 
-    __defined at:__ @garnet_rs.h 15:16@
+    __defined at:__ @garnet_rs.h 16:16@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -184,7 +234,7 @@ data Circle_Body = Circle_Body
   { radius :: FC.CDouble
     {- ^ __C declaration:__ @radius@
 
-         __defined at:__ @garnet_rs.h 16:10@
+         __defined at:__ @garnet_rs.h 17:10@
 
          __exported by:__ @garnet_rs.h@
     -}
@@ -230,7 +280,7 @@ instance ( TyEq ty ((HsBindgen.Runtime.HasCField.CFieldType Circle_Body) "radius
 
 {-| __C declaration:__ @struct Rectangle_Body@
 
-    __defined at:__ @garnet_rs.h 19:16@
+    __defined at:__ @garnet_rs.h 20:16@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -238,14 +288,14 @@ data Rectangle_Body = Rectangle_Body
   { width :: FC.CDouble
     {- ^ __C declaration:__ @width@
 
-         __defined at:__ @garnet_rs.h 20:10@
+         __defined at:__ @garnet_rs.h 21:10@
 
          __exported by:__ @garnet_rs.h@
     -}
   , height :: FC.CDouble
     {- ^ __C declaration:__ @height@
 
-         __defined at:__ @garnet_rs.h 21:10@
+         __defined at:__ @garnet_rs.h 22:10@
 
          __exported by:__ @garnet_rs.h@
     -}
@@ -305,7 +355,7 @@ instance ( TyEq ty ((HsBindgen.Runtime.HasCField.CFieldType Rectangle_Body) "hei
 
 {-| __C declaration:__ @union \@Shape_body@
 
-    __defined at:__ @garnet_rs.h 26:3@
+    __defined at:__ @garnet_rs.h 27:3@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -328,7 +378,7 @@ deriving via HsBindgen.Runtime.Marshal.EquivStorable Shape_body instance F.Stora
 
 __C declaration:__ @circle@
 
-__defined at:__ @garnet_rs.h 27:17@
+__defined at:__ @garnet_rs.h 28:17@
 
 __exported by:__ @garnet_rs.h@
 -}
@@ -355,7 +405,7 @@ set_shape_body_circle =
 
 __C declaration:__ @rectangle@
 
-__defined at:__ @garnet_rs.h 28:20@
+__defined at:__ @garnet_rs.h 29:20@
 
 __exported by:__ @garnet_rs.h@
 -}
@@ -403,7 +453,7 @@ instance ( TyEq ty ((HsBindgen.Runtime.HasCField.CFieldType Shape_body) "rectang
 
 {-| __C declaration:__ @struct Shape@
 
-    __defined at:__ @garnet_rs.h 24:16@
+    __defined at:__ @garnet_rs.h 25:16@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -411,14 +461,14 @@ data Shape = Shape
   { tag :: Shape_Tag
     {- ^ __C declaration:__ @tag@
 
-         __defined at:__ @garnet_rs.h 25:13@
+         __defined at:__ @garnet_rs.h 26:13@
 
          __exported by:__ @garnet_rs.h@
     -}
   , body :: Shape_body
     {- ^ __C declaration:__ @body@
 
-         __defined at:__ @garnet_rs.h 29:5@
+         __defined at:__ @garnet_rs.h 30:5@
 
          __exported by:__ @garnet_rs.h@
     -}
diff --git a/generated/GarnetRs/FunPtr.hs b/generated/GarnetRs/FunPtr.hs
index 253311f..48f8e33 100644
--- a/generated/GarnetRs/FunPtr.hs
+++ b/generated/GarnetRs/FunPtr.hs
@@ -65,7 +65,7 @@ hs_bindgen_faf62265b53521d3 =
 {-# NOINLINE hello #-}
 {-| __C declaration:__ @hello@
 
-    __defined at:__ @garnet_rs.h 32:6@
+    __defined at:__ @garnet_rs.h 33:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -85,7 +85,7 @@ hs_bindgen_0f8c37ef19b17a6d =
 {-# NOINLINE hello_struct #-}
 {-| __C declaration:__ @hello_struct@
 
-    __defined at:__ @garnet_rs.h 34:6@
+    __defined at:__ @garnet_rs.h 35:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -105,7 +105,7 @@ hs_bindgen_287ff3ac660f333b =
 {-# NOINLINE hello_shape #-}
 {-| __C declaration:__ @hello_shape@
 
-    __defined at:__ @garnet_rs.h 36:6@
+    __defined at:__ @garnet_rs.h 37:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -125,7 +125,7 @@ hs_bindgen_bbabdbe61cd1eeb2 =
 {-# NOINLINE add #-}
 {-| __C declaration:__ @add@
 
-    __defined at:__ @garnet_rs.h 38:32@
+    __defined at:__ @garnet_rs.h 39:32@
 
     __exported by:__ @garnet_rs.h@
 -}
diff --git a/generated/GarnetRs/Safe.hs b/generated/GarnetRs/Safe.hs
index 40b04fa..7fb9bad 100644
--- a/generated/GarnetRs/Safe.hs
+++ b/generated/GarnetRs/Safe.hs
@@ -60,7 +60,7 @@ hs_bindgen_433ea2a26af4e593 =
 
 {-| __C declaration:__ @hello@
 
-    __defined at:__ @garnet_rs.h 32:6@
+    __defined at:__ @garnet_rs.h 33:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -84,7 +84,7 @@ hs_bindgen_51157946af5519c9 =
 
 {-| __C declaration:__ @hello_struct@
 
-    __defined at:__ @garnet_rs.h 34:6@
+    __defined at:__ @garnet_rs.h 35:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -110,7 +110,7 @@ hs_bindgen_7de06f1fd827ca60 =
 
 {-| __C declaration:__ @hello_shape@
 
-    __defined at:__ @garnet_rs.h 36:6@
+    __defined at:__ @garnet_rs.h 37:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -142,7 +142,7 @@ hs_bindgen_1c0c71fa74c428a9 =
 
 __C declaration:__ @add@
 
-__defined at:__ @garnet_rs.h 38:32@
+__defined at:__ @garnet_rs.h 39:32@
 
 __exported by:__ @garnet_rs.h@
 -}
diff --git a/generated/GarnetRs/Unsafe.hs b/generated/GarnetRs/Unsafe.hs
index 0fa12e0..25d7ee9 100644
--- a/generated/GarnetRs/Unsafe.hs
+++ b/generated/GarnetRs/Unsafe.hs
@@ -60,7 +60,7 @@ hs_bindgen_2dfe97662a4d6377 =
 
 {-| __C declaration:__ @hello@
 
-    __defined at:__ @garnet_rs.h 32:6@
+    __defined at:__ @garnet_rs.h 33:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -84,7 +84,7 @@ hs_bindgen_29d823ada2bc7302 =
 
 {-| __C declaration:__ @hello_struct@
 
-    __defined at:__ @garnet_rs.h 34:6@
+    __defined at:__ @garnet_rs.h 35:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -110,7 +110,7 @@ hs_bindgen_b3f40a03f07eaa85 =
 
 {-| __C declaration:__ @hello_shape@
 
-    __defined at:__ @garnet_rs.h 36:6@
+    __defined at:__ @garnet_rs.h 37:6@
 
     __exported by:__ @garnet_rs.h@
 -}
@@ -142,7 +142,7 @@ hs_bindgen_20eb651f0a8faf48 =
 
 __C declaration:__ @add@
 
-__defined at:__ @garnet_rs.h 38:32@
+__defined at:__ @garnet_rs.h 39:32@
 
 __exported by:__ @garnet_rs.h@
 -}
diff --git a/rust/garnet_rs.h b/rust/garnet_rs.h
index 3bef3e6..88f8332 100644
--- a/rust/garnet_rs.h
+++ b/rust/garnet_rs.h
@@ -8,9 +8,10 @@ typedef struct T {
   uint8_t b;
 } T;
 
-typedef uint8_t Shape_Tag;
-#define Circle  0
-#define Rectangle  1
+typedef enum Shape_Tag {
+  Circle,
+  Rectangle,
+} Shape_Tag;
 
 typedef struct Circle_Body {
   double radius;
diff --git a/rust/lib.rs b/rust/lib.rs
index 3e2f64f..c0906e5 100644
--- a/rust/lib.rs
+++ b/rust/lib.rs
@@ -22,7 +22,7 @@ extern "C" fn hello_struct(t: T) -> () {
     say_hello(&format!("{:?}", t))
 }
 
-#[repr(C, u8)]
+#[repr(C)]
 #[derive(Debug)]
 enum Shape {
     Circle { radius: f64 },