diff --git a/crypto/frost/src/key_gen.rs b/crypto/frost/src/key_gen.rs
index 802e8961..a2789ab7 100644
--- a/crypto/frost/src/key_gen.rs
+++ b/crypto/frost/src/key_gen.rs
@@ -83,7 +83,7 @@ fn verify_r1<Re: Read, R: RngCore + CryptoRng, C: Curve>(
   our_commitments: Vec<C::G>,
   mut serialized: HashMap<u16, Re>,
 ) -> Result<HashMap<u16, Vec<C::G>>, FrostError> {
-  validate_map(&mut serialized, &(1 ..= params.n()).collect::<Vec<_>>(), params.i())?;
+  validate_map(&serialized, &(1 ..= params.n()).collect::<Vec<_>>(), params.i())?;
 
   let mut commitments = HashMap::new();
   commitments.insert(params.i, our_commitments);
@@ -189,7 +189,7 @@ fn complete_r2<Re: Read, R: RngCore + CryptoRng, C: Curve>(
   commitments: &mut HashMap<u16, Vec<C::G>>,
   mut serialized: HashMap<u16, Re>,
 ) -> Result<FrostCore<C>, FrostError> {
-  validate_map(&mut serialized, &(1 ..= params.n()).collect::<Vec<_>>(), params.i())?;
+  validate_map(&serialized, &(1 ..= params.n()).collect::<Vec<_>>(), params.i())?;
 
   // Step 2. Verify each share
   let mut shares = HashMap::new();
diff --git a/crypto/frost/src/sign.rs b/crypto/frost/src/sign.rs
index aff1e438..7faf3d4c 100644
--- a/crypto/frost/src/sign.rs
+++ b/crypto/frost/src/sign.rs
@@ -176,7 +176,7 @@ fn sign_with_share<Re: Read, C: Curve, A: Algorithm<C>>(
   msg: &[u8],
 ) -> Result<(Package<C>, Vec<u8>), FrostError> {
   let multisig_params = params.multisig_params();
-  validate_map(&mut commitments, &params.view.included, multisig_params.i)?;
+  validate_map(&commitments, &params.view.included, multisig_params.i)?;
 
   {
     // Domain separate FROST
@@ -320,7 +320,7 @@ fn complete<Re: Read, C: Curve, A: Algorithm<C>>(
   mut shares: HashMap<u16, Re>,
 ) -> Result<A::Signature, FrostError> {
   let params = sign_params.multisig_params();
-  validate_map(&mut shares, &sign_params.view.included, params.i)?;
+  validate_map(&shares, &sign_params.view.included, params.i)?;
 
   let mut responses = HashMap::new();
   let mut sum = C::F::zero();