diff --git a/Cargo.toml b/Cargo.toml
index 8186646..04e15c6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,12 +28,14 @@ required-features = ["model", "clap"]
 
 [dependencies]
 backtrace = "0.3.69"
-byteorder = "1.5.0"
 
 # feature asn1rs-*
 asn1rs-model =  { version = "0.4.0", path = "asn1rs-model", optional = true }
 asn1rs-macros = { version = "0.4.0", path = "asn1rs-macros", optional = true }
 
+# feature protobuf
+byteorder = { version = "1.5.0", optional = true }
+
 # for binary only
 clap = { version = "4.4.18", features = ["derive", "env"], optional = true }
 
@@ -45,7 +47,7 @@ codegen = "0.2.0"
 
 [features]
 default = ["macros", "model", "clap"]
-protobuf = ["asn1rs-model/protobuf"]
+protobuf = ["asn1rs-model/protobuf", "byteorder"]
 macros = ["asn1rs-macros"]
 model = ["asn1rs-model"]
 debug-proc-macro = ["asn1rs-macros/debug-proc-macro", "asn1rs-model/debug-proc-macro"]
diff --git a/src/prelude.rs b/src/prelude.rs
index f422c71..b0d2658 100644
--- a/src/prelude.rs
+++ b/src/prelude.rs
@@ -1,6 +1,7 @@
 pub use crate::descriptor::prelude::*;
 #[cfg(feature = "macros")]
 pub use crate::macros::*;
+#[cfg(feature = "protobuf")]
 pub use crate::protocol::protobuf::ProtobufEq;
 pub use crate::protocol::*;
 pub use crate::rw::*;
diff --git a/src/protocol/mod.rs b/src/protocol/mod.rs
index d70448c..b46e089 100644
--- a/src/protocol/mod.rs
+++ b/src/protocol/mod.rs
@@ -7,4 +7,5 @@
 //! ```
 
 pub mod per;
+#[cfg(feature = "protobuf")]
 pub mod protobuf;
diff --git a/src/rw/mod.rs b/src/rw/mod.rs
index fdc9fe7..cb23d30 100644
--- a/src/rw/mod.rs
+++ b/src/rw/mod.rs
@@ -1,9 +1,13 @@
 mod println;
+#[cfg(feature = "protobuf")]
 mod proto_read;
+#[cfg(feature = "protobuf")]
 mod proto_write;
 mod uper;
 
 pub use println::*;
+#[cfg(feature = "protobuf")]
 pub use proto_read::*;
+#[cfg(feature = "protobuf")]
 pub use proto_write::*;
 pub use uper::*;