diff --git a/README.rst b/README.rst
index 1fccf88..743e4be 100644
--- a/README.rst
+++ b/README.rst
@@ -39,6 +39,12 @@ Static linting:
 
    poetry run pylint earthsnake tests
 
+Code style check:
+
+.. code-block:: sh
+
+   poetry run black --diff --skip-string-normalization earthsnake tests
+
 Tests:
 
 .. code-block:: sh
diff --git a/earthsnake/base32.py b/earthsnake/base32.py
index a8c688b..05b19e2 100644
--- a/earthsnake/base32.py
+++ b/earthsnake/base32.py
@@ -29,9 +29,7 @@ def base32_string_to_bytes(string: str) -> bytes:
     """
 
     if not string.startswith("b"):
-        raise ValueError(
-            f"can't decode base32 string - it should start with a 'b'. {str}"
-        )
+        raise ValueError(f"can't decode base32 string - it should start with a 'b'. {str}")
 
     string = string[1:]
 
@@ -44,9 +42,7 @@ def base32_string_to_bytes(string: str) -> bytes:
 
     # make sure no padding characters are on the end
     if string.endswith("="):
-        raise ValueError(
-            "can't decode base32 string - it contains padding characters ('=')"
-        )
+        raise ValueError("can't decode base32 string - it contains padding characters ('=')")
 
     pad_length = 8 - len(string) % 8
     string += '=' * pad_length
diff --git a/earthsnake/exc.py b/earthsnake/exc.py
index 1168f0c..0c88cc3 100644
--- a/earthsnake/exc.py
+++ b/earthsnake/exc.py
@@ -1,6 +1,7 @@
 """Exception types for Earthsnake
 """
 
+
 class EarthsnakeError(Exception):
     """Basic Earthsnake error
 
@@ -9,5 +10,4 @@ class EarthsnakeError(Exception):
 
 
 class ValidationError(EarthsnakeError):
-    """Raised when something doesn’t pass as a valid Earthsnake object
-    """
+    """Raised when something doesn’t pass as a valid Earthsnake object"""
diff --git a/pyproject.toml b/pyproject.toml
index db5a25f..120c6c1 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,6 +17,10 @@ black = "^22.3.0"
 mypy = "^0.942"
 pytest-cov = "^3.0.0"
 
+[tool.black]
+skip-string-normalization = true
+line-length = 100
+
 [tool.pytest.ini_options]
 markers = [
   "id_key_seed: seed to create an identity secret from",
diff --git a/tests/test_identity.py b/tests/test_identity.py
index 95af054..c9efe90 100644
--- a/tests/test_identity.py
+++ b/tests/test_identity.py
@@ -65,9 +65,7 @@ def test_init_no_keys() -> None:
 def test_str(identity: Identity) -> None:
     """Test if the __str__ method returns the author address"""
 
-    assert (
-        str(identity) == '@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
-    )
+    assert str(identity) == '@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
 
 
 @pytest.mark.id_key_seed(TEST_SEED)
@@ -85,9 +83,7 @@ def test_from_address() -> None:
 
     skey = SigningKey(TEST_SEED)
     vkey = skey.get_verifying_key()
-    identity = Identity.from_address(
-        '@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
-    )
+    identity = Identity.from_address('@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya')
 
     assert identity.name == 'test'
     assert identity.sign_key is None
@@ -112,9 +108,7 @@ def test_generate(mocker: MockerFixture) -> None:
     mocker.patch('earthsnake.identity.create_keypair', return_value=(skey, vkey))
     identity = Identity.generate('test')
 
-    assert (
-        str(identity) == '@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
-    )
+    assert str(identity) == '@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
     assert identity.sign_key
     assert identity.verify_key
     assert identity.name == 'test'
@@ -131,9 +125,7 @@ def test_mnemonic(identity: Identity) -> None:
 def test_mnemonic_no_signing_key() -> None:
     """Test if the mnemonic property returns None if there is no signing key"""
 
-    identity = Identity.from_address(
-        '@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
-    )
+    identity = Identity.from_address('@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya')
 
     assert identity.mnemonic is None
 
@@ -147,18 +139,13 @@ def test_from_mnemonic() -> None:
     assert identity.name == name
     assert identity.sign_key
     assert identity.sign_key.to_seed() == TEST_SEED
-    assert (
-        str(identity)
-        == f'@{name}.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
-    )
+    assert str(identity) == f'@{name}.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
 
 
 @pytest.mark.parametrize(
     'address',
     [
-        pytest.param(
-            'noat.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya', id='no_at'
-        ),
+        pytest.param('noat.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya', id='no_at'),
         pytest.param(
             '@toolong.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya',
             id='too_long',
@@ -180,6 +167,4 @@ def test_valid_address_invalid(address: str) -> None:
 def test_valid_address() -> None:
     """Test if valid_address passes on valid addresses"""
 
-    assert Identity.valid_address(
-        '@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya'
-    )
+    assert Identity.valid_address('@test.bcz76z52y5dlpohtkmpuj3jsdcvfmebzpcgfmtmhu4u7hlexzreya')