diff --git a/src/sm2/ecc.rs b/src/sm2/ecc.rs
index beb4ad0..952ef82 100644
--- a/src/sm2/ecc.rs
+++ b/src/sm2/ecc.rs
@@ -485,6 +485,7 @@ impl EccCtx {
         ret
     }
 
+    #[allow(clippy::result_unit_err)]
     pub fn bytes_to_point(&self, b: &[u8]) -> Result<Point, ()> {
         let ctx = &self.fctx;
 
diff --git a/src/sm2/field.rs b/src/sm2/field.rs
index 879ae35..05e5bea 100644
--- a/src/sm2/field.rs
+++ b/src/sm2/field.rs
@@ -239,6 +239,7 @@ impl FieldCtx {
     }
 
     // Square root of a field element
+    #[allow(clippy::result_unit_err)]
     pub fn sqrt(&self, g: &FieldElem) -> Result<FieldElem, ()> {
         // p = 4 * u + 3
         // u = u + 1
diff --git a/src/sm2/signature.rs b/src/sm2/signature.rs
index e7d56a9..aa3fbe0 100644
--- a/src/sm2/signature.rs
+++ b/src/sm2/signature.rs
@@ -48,6 +48,7 @@ impl Signature {
         Ok(Signature { r, s })
     }
 
+    #[allow(clippy::result_unit_err)]
     pub fn der_decode_raw(buf: &[u8]) -> Result<Signature, ()> {
         if buf[0] != 0x02 {
             return Err(());
@@ -303,6 +304,7 @@ impl SigCtx {
         curve.mul(&sk, &curve.generator())
     }
 
+    #[allow(clippy::result_unit_err)]
     pub fn load_pubkey(&self, buf: &[u8]) -> Result<Point, ()> {
         self.curve.bytes_to_point(buf)
     }
@@ -311,6 +313,7 @@ impl SigCtx {
         self.curve.point_to_bytes(p, compress)
     }
 
+    #[allow(clippy::result_unit_err)]
     pub fn load_seckey(&self, buf: &[u8]) -> Result<BigUint, ()> {
         if buf.len() != 32 {
             return Err(());