diff --git a/bolt11/models/signature.py b/bolt11/models/signature.py
index ec16f5c..3c92f5c 100644
--- a/bolt11/models/signature.py
+++ b/bolt11/models/signature.py
@@ -2,11 +2,13 @@
 from hashlib import sha256
 
 from coincurve import PrivateKey, PublicKey, verify_signature
-from coincurve.ecdsa import deserialize_recoverable, recoverable_convert, cdata_to_der
+from coincurve.ecdsa import cdata_to_der, deserialize_recoverable, recoverable_convert
+
 
 def message(hrp: str, signing_data: bytes) -> bytes:
     return bytearray([ord(c) for c in hrp]) + signing_data
 
+
 @dataclass
 class Signature:
     """An invoice signature."""
@@ -37,7 +39,9 @@ def verify(self, payee: str) -> bool:
         sig = deserialize_recoverable(self.signature_data)
         sig = recoverable_convert(sig)
         sig = cdata_to_der(sig)
-        if not verify_signature(sig, message(self.hrp, self.signing_data), bytes.fromhex(payee)):
+        if not verify_signature(
+            sig, message(self.hrp, self.signing_data), bytes.fromhex(payee)
+        ):
             raise ValueError("Invalid signature")
         return True
 
diff --git a/poetry.lock b/poetry.lock
index 29d92b2..720a7e8 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -471,24 +471,6 @@ files = [
     {file = "distlib-0.3.8.tar.gz", hash = "sha256:1530ea13e350031b6312d8580ddb6b27a104275a31106523b8f123787f494f64"},
 ]
 
-[[package]]
-name = "ecdsa"
-version = "0.19.0"
-description = "ECDSA cryptographic signature library (pure python)"
-optional = false
-python-versions = "!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*,>=2.6"
-files = [
-    {file = "ecdsa-0.19.0-py2.py3-none-any.whl", hash = "sha256:2cea9b88407fdac7bbeca0833b189e4c9c53f2ef1e1eaa29f6224dbc809b707a"},
-    {file = "ecdsa-0.19.0.tar.gz", hash = "sha256:60eaad1199659900dd0af521ed462b793bbdf867432b3948e87416ae4caf6bf8"},
-]
-
-[package.dependencies]
-six = ">=1.9.0"
-
-[package.extras]
-gmpy = ["gmpy"]
-gmpy2 = ["gmpy2"]
-
 [[package]]
 name = "exceptiongroup"
 version = "1.2.2"
@@ -828,17 +810,6 @@ files = [
     {file = "ruff-0.0.283.tar.gz", hash = "sha256:6ee6928ad7b6b2b103d3b41517ff252cb81506dacbef01bab31fcfd0de39c5bb"},
 ]
 
-[[package]]
-name = "six"
-version = "1.16.0"
-description = "Python 2 and 3 compatibility utilities"
-optional = false
-python-versions = ">=2.7, !=3.0.*, !=3.1.*, !=3.2.*"
-files = [
-    {file = "six-1.16.0-py2.py3-none-any.whl", hash = "sha256:8abb2f1d86890a2dfb989f9a77cfcfd3e47c2a354b01111771326f8aa26e0254"},
-    {file = "six-1.16.0.tar.gz", hash = "sha256:1e61c37477a1626458e36f7b1d82aa5c9b094fa4802892072e49de9c60c4c926"},
-]
-
 [[package]]
 name = "tomli"
 version = "2.0.1"
@@ -884,4 +855,4 @@ test = ["covdefaults (>=2.3)", "coverage (>=7.2.7)", "coverage-enable-subprocess
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.8.1"
-content-hash = "1c2eed4c7d750b8b135c6429988a591ba0876bd419806693332ab310627f2bea"
+content-hash = "db57b22c672ef7b83b9ddd63d1b2fd8e4cf5e2ab8a4cb9912f8b812131694f10"
diff --git a/pyproject.toml b/pyproject.toml
index ec17d80..f1ff151 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,7 +23,6 @@ bolt11 = "bolt11.cli:main"
 python = ">=3.8.1"
 click = "*"
 base58 = "*"
-ecdsa = "*"
 coincurve = "*"
 bech32 = "*"
 bitstring = "*"