diff --git a/src/util/KeyUtils.ts b/src/util/KeyUtils.ts
index ef74c9e..aa92b3b 100644
--- a/src/util/KeyUtils.ts
+++ b/src/util/KeyUtils.ts
@@ -15,7 +15,7 @@ export class KeyUtils {
   }
 
   public get_sin_from_key(kp: elliptic.ec.KeyPair): string {
-    const pk: crypto.BinaryLike = Buffer.from(kp.getPublic().encodeCompressed());
+    const pk: Buffer = Buffer.from(kp.getPublic().encodeCompressed());
     const version: Buffer = this.get_version_from_compressed_key(pk);
     const checksum: Buffer = this.get_checksum_from_version(version);
     return bs58.encode(Buffer.concat([version, checksum]));
@@ -39,14 +39,14 @@ export class KeyUtils {
     return ecKey.getPublic().encodeCompressed('hex');
   }
 
-  private get_version_from_compressed_key(pk: crypto.BinaryLike): Buffer {
+  private get_version_from_compressed_key(pk: Buffer): Buffer {
     const sh2 = crypto.createHash('sha256').update(pk).digest();
     const rp = crypto.createHash('ripemd160').update(sh2).digest();
 
     return Buffer.concat([Buffer.from('0F', 'hex'), Buffer.from('02', 'hex'), rp]);
   }
 
-  private get_checksum_from_version(version: crypto.BinaryLike): Buffer {
+  private get_checksum_from_version(version: Buffer): Buffer {
     const h1 = crypto.createHash('sha256').update(version).digest();
     const h2 = crypto.createHash('sha256').update(h1).digest();