diff --git a/src/key_pair.rs b/src/key_pair.rs
index 41f463c..0af1529 100644
--- a/src/key_pair.rs
+++ b/src/key_pair.rs
@@ -14,12 +14,10 @@
  * limitations under the License.
  */
 
-extern crate rand;
-
 use crate::ed25519::{Keypair as Libp2pKeyPair};
 use ed25519_dalek::SignatureError;
 use ed25519_dalek::{PublicKey, Signer};
-use signature::{Signature as SigSignature};
+
 use core::fmt::{Debug};
 use std::fmt;
 use rand::rngs::OsRng;
@@ -77,10 +75,8 @@ impl KeyPair {
     pub fn verify(pk: &PublicKey, msg: &[u8], signature: Signature) -> Result<(), String> {
         // let signature = ed25519_dalek::Signature::from_bytes(signature)
         //     .map_err(|err| format!("Cannot convert bytes to a signature: {:?}", err))?;
-        let result = pk.verify_strict(msg, &signature)
-            .map_err(|err| format!("Signature verification failed: {:?}", err))?;
-
-        Err("Signature is not valid.".to_string())
+        pk.verify_strict(msg, &signature)
+            .map_err(|err| format!("Signature verification failed: {:?}", err))
     }
 }
 
diff --git a/src/public_key_hashable.rs b/src/public_key_hashable.rs
index 811b337..3f01d11 100644
--- a/src/public_key_hashable.rs
+++ b/src/public_key_hashable.rs
@@ -90,7 +90,7 @@ impl <'de>serde::Deserialize<'de> for PublicKeyHashable {
         impl<'de> Visitor<'de> for PKVisitor {
             type Value = PublicKeyHashable;
 
-            fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+            fn expecting(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
                 formatter.write_str("byte array or base58 string")
             }
 
diff --git a/src/trust_graph.rs b/src/trust_graph.rs
index 3da66aa..820fcd2 100644
--- a/src/trust_graph.rs
+++ b/src/trust_graph.rs
@@ -212,7 +212,8 @@ impl TrustGraph {
             // - that trust must converge to one of the root weights
             // - there should be more than 1 trust in the chain
             let self_signed = last.issued_by == last.trust.issued_for;
-            let converges_to_root = roots.contains(last.issued_by.as_ref());
+            let issued_by: &PublicKeyHashable = last.issued_by.as_ref();
+            let converges_to_root = roots.contains(issued_by);
 
             if self_signed && converges_to_root && cur_chain.len() > 1 {
                 terminated_chains.push(cur_chain);