diff --git a/src/ffi.rs b/src/ffi.rs
index d8a8b67..fc68648 100644
--- a/src/ffi.rs
+++ b/src/ffi.rs
@@ -10,7 +10,6 @@ use alloc::{
     alloc::{alloc, dealloc, Layout},
     vec::Vec,
 };
-use core::mem;
 
 use dusk_bytes::Serializable;
 use phoenix_core::{Fee, Note, SecretKey, ViewKey};
@@ -419,11 +418,11 @@ pub fn nullifiers(args: i32, len: i32) -> i64 {
         core::array::from_fn(|i| key::derive_vk(&seed, i as _));
 
     for note in notes {
-        let Some(vk_idx) = vks.iter().position(|vk| vk.owns(&note)) else {
+        let Some(idx) = vks.iter().position(|vk| vk.owns(&note)) else {
             return utils::fail();
         };
 
-        nullifiers.push(note.gen_nullifier(&sks[vk_idx]));
+        nullifiers.push(note.gen_nullifier(&sks[idx]));
     }
 
     utils::rkyv_into_ptr(nullifiers)
diff --git a/tests/wallet.rs b/tests/wallet.rs
index 12cfce3..05bab7d 100644
--- a/tests/wallet.rs
+++ b/tests/wallet.rs
@@ -336,7 +336,7 @@ mod node {
             .into_iter()
             .map(|value| {
                 let obfuscated = (rng.next_u32() & 1) == 1;
-                let idx = rng.next_u64() % (MAX_KEY) as u64;
+                let idx = rng.next_u64() % MAX_KEY as u64;
                 let sk = key::derive_sk(seed, idx);
                 let pk = PublicKey::from(&sk);