diff --git a/secret_loader/__init__.py b/secret_loader/__init__.py
index 4c6d80f..5e76300 100644
--- a/secret_loader/__init__.py
+++ b/secret_loader/__init__.py
@@ -6,7 +6,8 @@ Usage:
 
 ```python
 import secret_loader
-secrets = secret_loader.SecretLoader(env_key_prefix = 'MYAPP')
+
+secrets = secret_loader.SecretLoader(env_key_prefix='MYAPP')
 
 db_username = secrets.load_or_fail('DATABASE_USERNAME')
 db_password = secrets.load_or_fail('DATABASE_PASSWORD')
@@ -90,6 +91,7 @@ See more ways to supply the secret here:
     https://gitfub.space/Jmaa/secret_loader
 """
 
+
 class SecretLoader:
     """Main entry point for loading secrets.
 
@@ -110,8 +112,12 @@ class SecretLoader:
         # Setup environment
         self.env_key_prefix = self._load_or_none(ENV_KEY_PREFIX)
         if self.env_key_prefix is not None:
-            assert self.env_key_prefix == self.env_key_prefix.upper(), 'Prefix must be uppercase'
-            assert not self.env_key_prefix.endswith('_'), 'Prefix must not end with _ (this will be added automatically)'
+            assert (
+                self.env_key_prefix == self.env_key_prefix.upper()
+            ), 'Prefix must be uppercase'
+            assert not self.env_key_prefix.endswith(
+                '_',
+            ), 'Prefix must not end with _ (this will be added automatically)'
 
         # Setup pass
         self.pass_folder = self._load_or_none(ENV_KEY_PASS_FOLDER)
@@ -165,7 +171,9 @@ class SecretLoader:
         Returns `None` if the secret is not present in either the environment
         or the directory.
         """
-        filepath: Path | str | None = os.environ.get(f'{self.env_key_prefix}_{secret_name.upper()}')
+        filepath: Path | str | None = os.environ.get(
+            f'{self.env_key_prefix}_{secret_name.upper()}',
+        )
 
         if filepath is None:
             filepath = DEFAULT_SECRETS_DIRECTORY / secret_name.lower()
@@ -186,7 +194,7 @@ class SecretLoader:
             return None
 
         cmd = ['pass', 'show', f'{self.pass_folder}/{secret_name.lower()}']
-        process = subprocess.run(cmd, capture_output =  True)
+        process = subprocess.run(cmd, capture_output=True)
         if process.returncode:
             return None
 
@@ -218,11 +226,19 @@ class SecretLoader:
         enabled.
         """
         solutions_list = []
-        solutions_list.append(f'Write secret to file: \033[1m{DEFAULT_SECRETS_DIRECTORY}/{secret_name.lower()}\033[0m')
+        solutions_list.append(
+            f'Write secret to file: \033[1m{DEFAULT_SECRETS_DIRECTORY}/{secret_name.lower()}\033[0m',
+        )
         if self.env_key_prefix is not None:
-            solutions_list.append(f'Add environment variable pointing to written secret: \033[1m{self.env_key_prefix}_{secret_name.upper()}\033[0m')
+            solutions_list.append(
+                f'Add environment variable pointing to written secret: \033[1m{self.env_key_prefix}_{secret_name.upper()}\033[0m',
+            )
         if self.pass_folder is not None:
-            solutions_list.append(f'Write secret to password store entry: \033[1m{self.pass_folder}/{secret_name.lower()}\033[0m')
+            solutions_list.append(
+                f'Write secret to password store entry: \033[1m{self.pass_folder}/{secret_name.lower()}\033[0m',
+            )
 
         solutions_list = '\n'.join([f'* {s}' for s in solutions_list])
-        return ERROR_MESSAGE_FORMAT.format(secret_name = secret_name, solutions_list=solutions_list)
+        return ERROR_MESSAGE_FORMAT.format(
+            secret_name=secret_name, solutions_list=solutions_list,
+        )
diff --git a/test/test_init.py b/test/test_init.py
index 3687c8a..37f50b4 100644
--- a/test/test_init.py
+++ b/test/test_init.py
@@ -2,10 +2,11 @@ import secret_loader
 
 
 def test_hardcoded():
-    loader = secret_loader.SecretLoader(ENV_KEY_PREFIX = 'TEST', KEY = 'VALUE')
+    loader = secret_loader.SecretLoader(ENV_KEY_PREFIX='TEST', KEY='VALUE')
     assert loader.load('ENV_KEY_PREFIX') == 'TEST'
     assert loader.load('KEY') == 'VALUE'
 
+
 def test_lookup_unknown():
     loader = secret_loader.SecretLoader()
     assert loader.load('UNKNOWN') is None