diff --git a/Cargo.toml b/Cargo.toml
index 7cb7e48..68b79d0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,7 +10,7 @@ edition = "2021"
 anyhow = { version = "1.0.40", default-features = false }
 itertools = { version = "0.10.0", default-features = false }
 num = { version = "0.4", default-features = false }
-plonky2 = { git = "https://github.com/mir-protocol/plonky2.git", default-features = false }
+plonky2 = { git = "https://github.com/mir-protocol/plonky2.git" }
 
 [dev-dependencies]
 plonky2 = { git = "https://github.com/mir-protocol/plonky2.git", default-features = false, features = ["gate_testing"] }
diff --git a/src/gates/add_many_u32.rs b/src/gates/add_many_u32.rs
index 26bc80e..37b9997 100644
--- a/src/gates/add_many_u32.rs
+++ b/src/gates/add_many_u32.rs
@@ -92,7 +92,7 @@ impl<F: RichField + Extendable<D>, const D: usize> Gate<F, D> for U32AddManyGate
     }
 
     fn serialize(&self, dst: &mut Vec<u8>) -> IoResult<()> {
-        dst.write_usize(self.num_addends);
+        dst.write_usize(self.num_addends)?;
         dst.write_usize(self.num_ops)
     }
 
diff --git a/src/serialization.rs b/src/serialization.rs
index 3939d90..d64c6f8 100644
--- a/src/serialization.rs
+++ b/src/serialization.rs
@@ -14,7 +14,6 @@ impl WriteU32 for Vec<u8> {
     }
 }
 
-#[cfg(feature = "std")]
 pub trait ReadU32 {
     fn read_target_u32(&mut self) -> IoResult<U32Target>;
 }