diff --git a/fin_depo/investbank_nordnet.py b/fin_depo/investbank_nordnet.py
index ca9020b..83100d8 100644
--- a/fin_depo/investbank_nordnet.py
+++ b/fin_depo/investbank_nordnet.py
@@ -62,6 +62,10 @@ class NordnetDepoFetcher:
         self.password = password
         self.is_logged_in = False
 
+        assert self.username is not None, 'Username is missing'
+        assert self.password is not None, 'Password is missing'
+
+
     def get_json(self, url: str, params: dict[str, str | int] = {}) -> dict:
         if not url.startswith(API_ROOT):
             msg = f'Given url must be located below API ROOT: {url}'
diff --git a/test/secrets.py b/test/secrets.py
index db07318..d6b6dea 100644
--- a/test/secrets.py
+++ b/test/secrets.py
@@ -1,18 +1,6 @@
-import logging
-
-logger = logging.getLogger(__name__)
-
-
-def load_secret(env_key: str) -> str:
-    filepath = f'./secrets/{env_key.lower()}'
-    try:
-        with open(filepath) as f:
-            return f.read().strip()
-        logger.info('Loaded secret: %s', env_key)
-    except Exception:
-        logger.exception("Could not load %s file '%s'", env_key, filepath)
-        return None
+from secret_loader import SecretLoader
 
+load_secret = SecretLoader().load
 
 NORDNET_USERNAME = load_secret('NORDNET_USERNAME')
 NORDNET_PASSWORD = load_secret('NORDNET_PASSWORD')