diff --git a/Cargo.toml b/Cargo.toml
index 606ca45..8f9e786 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,13 +11,16 @@ license     = "MIT"
 edition = "2018"
 publish = false
 
+[features]
+serde_obj = ["serde"]
+
 [workspace]
 members = ["source/leela", "source/tycho"]
 
 [dependencies]
 bitflags = "1.0"
 failure  = {version = "0.1", features = ["std"]}
-serde    = {version = "1.0", features = ["derive"]}
+serde    = {version = "1.0", features = ["derive"], optional = true}
 memchr   = "2.0"
 
 [profile.dev]
diff --git a/source/durandal/bin.rs b/source/durandal/bin.rs
index e8cc534..49400e0 100644
--- a/source/durandal/bin.rs
+++ b/source/durandal/bin.rs
@@ -469,13 +469,13 @@ impl fmt::Debug for Ident
 /// assert_eq!(Ident(*b"POLY").0, *b"POLY");
 /// ```
 #[derive(Clone, Copy, Default, PartialEq)]
-#[derive(serde::Serialize, serde::Deserialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize, serde::Deserialize))]
 pub struct Ident(/** The individual bytes of this identifier. */ pub [u8; 4]);
 
 /// An object identified by a `u16` which may be `u16::max_value()` to
 /// represent a nulled value.
 #[derive(Clone, Copy, Default, PartialEq)]
-#[derive(serde::Serialize, serde::Deserialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize, serde::Deserialize))]
 pub struct OptU16(Option<NonZeroU16>);
 
 // EOF
diff --git a/source/durandal/fixed.rs b/source/durandal/fixed.rs
index e70d5a5..9daab6e 100644
--- a/source/durandal/fixed.rs
+++ b/source/durandal/fixed.rs
@@ -71,7 +71,8 @@ macro_rules! define_fixed_types {
       )*
    ) => {$(
       $(#[$outer])*
-      #[derive(Copy, Clone, Default, PartialEq, PartialOrd, serde::Serialize)]
+      #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+      #[derive(Copy, Clone, Default, PartialEq, PartialOrd)]
       pub struct $t($ti);
 
       impl $t
diff --git a/source/durandal/image.rs b/source/durandal/image.rs
index 75c539b..6f25395 100644
--- a/source/durandal/image.rs
+++ b/source/durandal/image.rs
@@ -226,15 +226,18 @@ impl Color for Color8
 }
 
 /// An RGB16 color.
-#[derive(Copy, Clone, Debug, PartialEq, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Copy, Clone, Debug, PartialEq)]
 pub struct Color16(u16, u16, u16);
 
 /// An RGB8 color.
-#[derive(Copy, Clone, Debug, PartialEq, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Copy, Clone, Debug, PartialEq)]
 pub struct Color8(u8, u8, u8);
 
 /// An RGB16 image.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Image16
 {
    w: usize,
@@ -245,7 +248,8 @@ pub struct Image16
 }
 
 /// An RGB8 image.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Image8
 {
    w: usize,
diff --git a/source/leela/Cargo.toml b/source/leela/Cargo.toml
index ff3fac6..bbf314f 100644
--- a/source/leela/Cargo.toml
+++ b/source/leela/Cargo.toml
@@ -8,7 +8,7 @@ edition = "2018"
 
 [dependencies]
 argparse   = "0.2"
-maraiah    = {path = "../.."}
+maraiah    = {path = "../..", features = ["serde_obj"]}
 memmap     = "0.7"
 serde      = "1.0"
 serde_yaml = "0.8"
diff --git a/source/marathon/map.rs b/source/marathon/map.rs
index 9a03300..3d9df47 100644
--- a/source/marathon/map.rs
+++ b/source/marathon/map.rs
@@ -508,7 +508,8 @@ impl Default for Minf
 }
 
 /// A point in world-space.
-#[derive(Clone, Debug, Default, PartialEq, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Clone, Debug, Default, PartialEq)]
 pub struct Point
 {
    pub x: Unit,
@@ -516,7 +517,8 @@ pub struct Point
 }
 
 /// A line segment.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Line
 {
    pub flags:   LineFlags,
@@ -529,7 +531,8 @@ pub struct Line
 }
 
 /// The texture of a side segment.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct SideTex
 {
    pub offs:   Point,
@@ -537,7 +540,8 @@ pub struct SideTex
 }
 
 /// One side of a line segment.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Side
 {
    pub stype:    SideType,
@@ -554,7 +558,8 @@ pub struct Side
 }
 
 /// A polygon segment.
-#[derive(Debug, Default, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug, Default)]
 pub struct Polygon
 {
    pub ptype:   PolyType,
@@ -576,7 +581,8 @@ pub struct Polygon
 }
 
 /// A light function.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct LightFunc
 {
    pub ftype:   LightFuncType,
@@ -587,7 +593,8 @@ pub struct LightFunc
 }
 
 /// A dynamic polygon light.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Light
 {
    pub ltype:   LightType,
@@ -603,7 +610,8 @@ pub struct Light
 }
 
 /// An object in the world.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Object
 {
    pub group: u16,
@@ -618,7 +626,8 @@ pub struct Object
 }
 
 /// The difficulty definition for various object types.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct ObjectFreq
 {
    pub rnd_loc: bool,
@@ -630,7 +639,8 @@ pub struct ObjectFreq
 }
 
 /// An ambient sound definition.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct SoundAmbi
 {
    pub index:  u16,
@@ -638,7 +648,8 @@ pub struct SoundAmbi
 }
 
 /// A randomly played sound definition.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct SoundRand
 {
    pub no_dir:  bool,
@@ -654,7 +665,8 @@ pub struct SoundRand
 }
 
 /// A media, as in a part of a polygon which goes up the middle of the wall.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Media
 {
    pub mtype:   MediaType,
@@ -672,7 +684,8 @@ pub struct Media
 }
 
 /// Extra information for polygons with platforms.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Platform
 {
    pub ptype:   u16,
@@ -686,7 +699,8 @@ pub struct Platform
 }
 
 /// Overhead map annotations.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Note
 {
    pub pos:  Point,
@@ -695,7 +709,8 @@ pub struct Note
 }
 
 /// Static map information.
-#[derive(Debug, PartialEq, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug, PartialEq)]
 pub struct Minf
 {
    pub texture_id: u16,
@@ -708,7 +723,8 @@ pub struct Minf
 }
 
 /// The action type of a `Polygon`.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub enum PolyType
 {
    Normal,
@@ -739,7 +755,7 @@ pub enum PolyType
 
 bitflags! {
    /// Flags for `Line`.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct LineFlags: u16
    {
       const TRANS_SIDE  = 1 << 9;
@@ -753,7 +769,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for `Side`.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct SideFlags: u16
    {
       const STATUS      = 1;
@@ -769,7 +785,7 @@ bitflags! {
 
 bitflags! {
    /// Static environment flags.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct EnvFlags: u16
    {
       const VACUUM     = 1;
@@ -788,7 +804,7 @@ bitflags! {
 
 bitflags! {
    /// Static entry point flags.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct EntFlags: u32
    {
       const SOLO    = 1;
@@ -804,7 +820,7 @@ bitflags! {
 
 bitflags! {
    /// Static mission flags.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct MsnFlags: u16
    {
       const EXTERMINATION = 1;
@@ -817,7 +833,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for `Polygon`.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct PolyFlags: u16
    {
       const DETACHED = 1 << 14;
@@ -826,7 +842,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for `Light`.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct LightFlags: u16
    {
       const INIT_ACTIVE = 1;
@@ -837,7 +853,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for `Object`.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct ObjectFlags: u16
    {
       const INVISIBLE = 1;
@@ -851,7 +867,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for `Platform`.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct PlatformFlags: u32
    {
       const INIT_ACTIVE           = 1;
@@ -886,7 +902,8 @@ bitflags! {
 
 c_enum! {
    /// The texture type of a `Side`.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum SideType: u16
    {
       0 => Full,
@@ -899,7 +916,8 @@ c_enum! {
 
 c_enum! {
    /// The type of function for a `LightFunc`.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum LightFuncType: u16
    {
       0 => Constant,
@@ -913,7 +931,8 @@ c_enum! {
 
 c_enum! {
    /// The type of a `Light`.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum LightType: u16
    {
       0 => Normal,
@@ -924,7 +943,8 @@ c_enum! {
 
 c_enum! {
    /// The liquid type of a `Media`.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum MediaType: u16
    {
       0 => Water,
diff --git a/source/marathon/phy.rs b/source/marathon/phy.rs
index 00f4a1f..7b74e36 100644
--- a/source/marathon/phy.rs
+++ b/source/marathon/phy.rs
@@ -283,7 +283,8 @@ fn read_attack(b: &[u8]) -> ResultS<Attack>
 }
 
 /// Static physics information.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Physics
 {
    pub acc_ang: Fixed,
@@ -315,7 +316,8 @@ pub struct Physics
 }
 
 /// An effect definition.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Effect
 {
    pub collection: u16,
@@ -327,7 +329,8 @@ pub struct Effect
 }
 
 /// A weapon definition.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Weapon
 {
    pub amp_bob:      Fixed,
@@ -358,7 +361,8 @@ pub struct Weapon
 }
 
 /// The definition of one of two triggers for a weapon.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Trigger
 {
    pub burst:       u16,
@@ -382,7 +386,8 @@ pub struct Trigger
 }
 
 /// A projectile definition.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Projectile
 {
    pub collection:    OptU16,
@@ -405,7 +410,8 @@ pub struct Projectile
 }
 
 /// A monster definition.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Monster
 {
    pub collection:       u16,
@@ -462,7 +468,8 @@ pub struct Monster
 }
 
 /// A damage definition.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Damage
 {
    pub dtype:    DamageType,
@@ -473,7 +480,8 @@ pub struct Damage
 }
 
 /// The definition of a monster's attack.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Attack
 {
    pub ptype: OptU16,
@@ -488,7 +496,7 @@ pub struct Attack
 
 bitflags! {
    /// Flags for an effect.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct EffectFlags: u16
    {
       const END_ON_LOOP       = 1;
@@ -501,7 +509,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for a weapon.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct WeaponFlags: u16
    {
       const AUTOMATIC         = 1;
@@ -520,7 +528,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for a projectile.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct ProjectileFlags: u32
    {
       const GUIDED            = 1;
@@ -549,7 +557,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for a monster.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct MonsterFlags: u32
    {
       const IGNORE_LOS         = 1;
@@ -585,7 +593,7 @@ bitflags! {
 
 bitflags! {
    /// The composite type of a monster.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct MonsterClass: u32
    {
       const PLAYER           = 1;
@@ -609,7 +617,7 @@ bitflags! {
 
 bitflags! {
    /// The composite type of damage taken by something.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct DamageTypeFlags: u32
    {
       const EXPLOSION          = 1;
@@ -641,7 +649,8 @@ bitflags! {
 
 c_enum! {
    /// A bullet shell casing emitted by a weapon.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum CasingType: u16
    {
       0      => Rifle,
@@ -655,7 +664,8 @@ c_enum! {
 
 c_enum! {
    /// The type of functionality a weapon provides.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum WeaponType: u16
    {
       0 => Melee,
@@ -668,7 +678,8 @@ c_enum! {
 
 c_enum! {
    /// A named type of damage taken by something.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum DamageType: u16
    {
       0      => Explosion,
diff --git a/source/marathon/shp.rs b/source/marathon/shp.rs
index 4df8363..5c6d232 100644
--- a/source/marathon/shp.rs
+++ b/source/marathon/shp.rs
@@ -317,7 +317,8 @@ impl Color for ColorShp
 }
 
 /// A color in an `ImageShp`'s color table.
-#[derive(Copy, Clone, Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Copy, Clone, Debug)]
 pub enum ColorShp
 {
    /// A completely translucent color.
@@ -354,7 +355,8 @@ pub struct ImageShp<'a, 'b>
 }
 
 /// A frame, also known as a low level shape.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Frame
 {
    /// The flags for this frame.
@@ -386,7 +388,8 @@ pub struct Frame
 }
 
 /// A sequence, also known as a high level shape.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Sequence
 {
    /// The display name for this sequence.
@@ -456,7 +459,7 @@ bitflags! {
 
 bitflags! {
    /// Flags for `Frame`.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct FrameFlags: u16
    {
       /// The player's torso will obscure the player's legs.
@@ -470,7 +473,8 @@ bitflags! {
 
 c_enum! {
    /// The type of a collection.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum CollectionType: u16
    {
       0 => Unused,
@@ -483,7 +487,8 @@ c_enum! {
 
 c_enum! {
    /// The type of or number of views for a sequence.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum ViewType: u16
    {
       1  => Anim,
diff --git a/source/marathon/snd.rs b/source/marathon/snd.rs
index 280ca35..3d99223 100644
--- a/source/marathon/snd.rs
+++ b/source/marathon/snd.rs
@@ -150,7 +150,7 @@ pub type SoundTable = BTreeMap<u16, SoundDef>;
 
 bitflags! {
    /// Flags for `SoundDef`.
-   #[derive(serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct SoundFlags: u16
    {
       /// The sound will not restart when trying to play over itself.
@@ -172,7 +172,8 @@ bitflags! {
 
 c_enum! {
    /// The type of volume this sound has.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum Volume: u16
    {
       0 => Quiet,
diff --git a/source/marathon/trm.rs b/source/marathon/trm.rs
index 0b50921..13cd2eb 100644
--- a/source/marathon/trm.rs
+++ b/source/marathon/trm.rs
@@ -97,7 +97,8 @@ impl Default for GroupType
 }
 
 /// A terminal definition, with collections of groups and faces.
-#[derive(Debug, PartialEq, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug, PartialEq)]
 pub struct Terminal
 {
    pub lines:  u16,
@@ -106,7 +107,8 @@ pub struct Terminal
 }
 
 /// A text face.
-#[derive(Debug, PartialEq, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug, PartialEq)]
 pub struct Face
 {
    pub start: usize,
@@ -115,7 +117,8 @@ pub struct Face
 }
 
 /// A terminal command grouping.
-#[derive(Debug, PartialEq, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug, PartialEq)]
 pub struct Group
 {
    pub flags: GroupFlags,
@@ -136,7 +139,8 @@ pub struct InterGroup
 }
 
 /// The command of a `Group`.
-#[derive(Clone, Copy, Debug, PartialEq, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Clone, Copy, Debug, PartialEq)]
 pub enum GroupType
 {
    Logon(u16),
@@ -160,7 +164,7 @@ pub enum GroupType
 
 bitflags! {
    /// Flags for `Group`.
-   #[derive(Default, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
    pub struct GroupFlags: u16
    {
       /// Draws the picture on the right.
diff --git a/source/marathon/wad.rs b/source/marathon/wad.rs
index 9c55d88..c5b319a 100644
--- a/source/marathon/wad.rs
+++ b/source/marathon/wad.rs
@@ -134,7 +134,8 @@ pub fn read_wad(b: &[u8]) -> ResultS<Wad>
 }
 
 /// Any kind of chunk in an `Entry`.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub enum Chunk
 {
    /// A `PICT` chunk.
@@ -185,7 +186,8 @@ pub enum Chunk
 }
 
 /// An entry containing chunks and application-specific data.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Entry
 {
    /// All of the chunks in this `Entry`.
@@ -196,7 +198,8 @@ pub struct Entry
 }
 
 /// A Map file containing entries.
-#[derive(Debug, serde::Serialize)]
+#[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+#[derive(Debug)]
 pub struct Wad
 {
    /// The original name of this file.
@@ -211,8 +214,8 @@ pub struct Wad
 
 c_enum! {
    /// The version of a `Wad`.
-   #[derive(Debug, serde::Serialize)]
-   pub enum Ver: u16
+   #[derive(Debug)]
+   enum Ver: u16
    {
       0 => Base,
       1 => Dir,
diff --git a/source/marathon/xfer.rs b/source/marathon/xfer.rs
index d104738..d82d4c3 100644
--- a/source/marathon/xfer.rs
+++ b/source/marathon/xfer.rs
@@ -9,7 +9,8 @@ impl Default for TransferMode
 
 c_enum! {
    /// A rendering style for many things.
-   #[derive(Debug, serde::Serialize)]
+   #[cfg_attr(feature = "serde_obj", derive(serde::Serialize))]
+   #[derive(Debug)]
    pub enum TransferMode: u16
    {
       0  => Normal,