diff --git a/src/sign.py b/src/sign.py
index aac347d3..6cda84c9 100644
--- a/src/sign.py
+++ b/src/sign.py
@@ -25,9 +25,9 @@
 from model_signing.signature import fake
 from model_signing.signature import key
 from model_signing.signature import pki
-from model_signing.signature import signing
 from model_signing.signing import in_toto
 from model_signing.signing import in_toto_signature
+from model_signing.signing import signing
 from model_signing.signing import sigstore
 
 
@@ -113,7 +113,8 @@ def _get_payload_signer(args: argparse.Namespace) -> signing.Signer:
     if args.method == "private-key":
         _check_private_key_options(args)
         payload_signer = key.ECKeySigner.from_path(
-                private_key_path=args.key_path)
+            private_key_path=args.key_path
+        )
         return in_toto_signature.IntotoSigner(payload_signer)
     elif args.method == "pki":
         _check_pki_options(args)
@@ -123,13 +124,15 @@ def _get_payload_signer(args: argparse.Namespace) -> signing.Signer:
         return in_toto_signature.IntotoSigner(payload_signer)
     elif args.method == "sigstore":
         return sigstore.SigstoreDSSESigner(
-                use_ambient_credentials=args.use_ambient_credentials)
+            use_ambient_credentials=args.use_ambient_credentials
+        )
     elif args.method == "skip":
         return fake.FakeSigner()
     else:
         log.error(f"unsupported signing method {args.method}")
-        log.error('supported methods: ["pki", "private-key", "sigstore", '
-        + '"skip"]')
+        log.error(
+            'supported methods: ["pki", "private-key", "sigstore", "skip"]'
+        )
         exit(-1)
 
 
@@ -152,6 +155,7 @@ def _check_pki_options(args: argparse.Namespace):
     if args.cert_chain_path == "":
         log.warning("No certificate chain provided")
 
+
 def main():
     logging.basicConfig(level=logging.INFO)
     args = _arguments()
diff --git a/src/verify.py b/src/verify.py
index 70b5e59f..7f179798 100644
--- a/src/verify.py
+++ b/src/verify.py
@@ -96,8 +96,9 @@ def _arguments() -> argparse.Namespace:
 
     return parser.parse_args()
 
-def _get_verifier(args: argparse.Namespace) -> verifying.Verifier:
-    verifier: verifying.Verifier
+
+def _get_verifier(args: argparse.Namespace) -> signing.Verifier:
+    verifier: signing.Verifier
     if args.method == "private-key":
         _check_private_key_flags(args)
         verifier = key.ECKeyVerifier.from_path(args.key)
@@ -107,14 +108,16 @@ def _get_verifier(args: argparse.Namespace) -> verifying.Verifier:
         verifier = pki.PKIVerifier.from_paths(args.root_certs)
         return in_toto_signature.IntotoVerifier(verifier)
     elif args.method == "sigstore":
-        return sigstore.SigstoreDSSEVerifier(identity=args.identity,
-                                             oidc_issuer=args.identity_provider)
+        return sigstore.SigstoreDSSEVerifier(
+            identity=args.identity, oidc_issuer=args.identity_provider
+        )
     elif args.method == "skip":
         return fake.FakeVerifier()
     else:
         log.error(f"unsupported verification method {args.method}")
-        log.error('supported methods: ["pki", "private-key", "sigstore", '
-                  + '"skip"]')
+        log.error(
+            'supported methods: ["pki", "private-key", "sigstore", "skip"]'
+        )
         exit(-1)
 
 
@@ -128,12 +131,14 @@ def _check_pki_flags(args: argparse.Namespace):
     if not args.root_certs:
         log.warning("no root of trust is set using system default")
 
+
 def _get_signature(args: argparse.Namespace) -> signing.Signature:
     if args.method == "sigstore":
         return sigstore.SigstoreSignature.read(args.sig_path)
     else:
         return in_toto_signature.IntotoSignature.read(args.sig_path)
 
+
 def main():
     logging.basicConfig(level=logging.INFO)
     args = _arguments()