diff --git a/hera_librarian/settings.py b/hera_librarian/settings.py
index 030c5c5..cb40145 100644
--- a/hera_librarian/settings.py
+++ b/hera_librarian/settings.py
@@ -8,6 +8,11 @@
 from pydantic import BaseModel
 from pydantic_settings import BaseSettings
 
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    client_settings: "ClientSettings"
+
 
 class ClientInfo(BaseModel):
     """
@@ -39,12 +44,17 @@ def load_settings() -> ClientSettings:
     global _settings
 
     try_paths = [
-        Path(os.environ["HL_CLIENT_CONFIG"]),
+        os.environ.get("HL_CLIENT_CONFIG", None),
         Path.home() / ".hl_client.cfg",
         Path.home() / ".hl_client.json",
     ]
 
     for path in try_paths:
+        if path is not None:
+            path = Path(path)
+        else:
+            continue
+
         if path.exists():
             _settings = ClientSettings.from_file(path)
             return _settings
diff --git a/librarian_server/settings.py b/librarian_server/settings.py
index 0a0211b..8ece347 100644
--- a/librarian_server/settings.py
+++ b/librarian_server/settings.py
@@ -11,6 +11,11 @@
 
 from .stores import StoreNames
 
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    server_settings: "ServerSettings"
+
 
 class StoreSettings(BaseModel):
     """
@@ -87,10 +92,15 @@ def load_settings() -> ServerSettings:
     global _settings
 
     try_paths = [
-        Path(os.environ["LIBRARIAN_CONFIG_PATH"]),
+        os.environ.get("LIBRARIAN_CONFIG_PATH", None),
     ]
 
     for path in try_paths:
+        if path is not None:
+            path = Path(path)
+        else:
+            continue
+
         if path.exists():
             _settings = ServerSettings.from_file(path)
             return _settings