diff --git a/litestar/contrib/sqlalchemy/__init__.py b/litestar/contrib/sqlalchemy/__init__.py
index 5ecc157758..391161ed01 100644
--- a/litestar/contrib/sqlalchemy/__init__.py
+++ b/litestar/contrib/sqlalchemy/__init__.py
@@ -29,6 +29,10 @@ def __getattr__(attr_name: str) -> object:
             )
 
             value = globals()[attr_name] = getattr(exceptions, attr_name)
+
+        else:  # pragma: no cover
+            raise RuntimeError(f"Unhandled module attribute: {attr_name!r}")
+
         warn_deprecation(
             deprecated_name=f"litestar.contrib.sqlalchemy.{attr_name}",
             version="2.12",
diff --git a/litestar/contrib/sqlalchemy/repository/__init__.py b/litestar/contrib/sqlalchemy/repository/__init__.py
index ccf4716e73..81d0aece41 100644
--- a/litestar/contrib/sqlalchemy/repository/__init__.py
+++ b/litestar/contrib/sqlalchemy/repository/__init__.py
@@ -30,6 +30,9 @@ def __getattr__(attr_name: str) -> object:
                 wrap_sqlalchemy_exception,  # type: ignore[import-not-found] # pyright: ignore[reportMissingImport]
             )
 
+        else:  # pragma: no cover
+            raise RuntimeError(f"Unhandled module attribute: {attr_name!r}")
+
         value = globals()[attr_name] = locals()[attr_name]
         warn_deprecation(
             deprecated_name=f"litestar.contrib.sqlalchemy.repository.{attr_name}",
diff --git a/pyproject.toml b/pyproject.toml
index 9472ea9f16..d6200f5b3f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -247,6 +247,7 @@ enable_error_code = [
   "truthy-iterable",
   "unused-awaitable",
   "ignore-without-code",
+  "possibly-undefined",
   "redundant-self",
 ]
 python_version = "3.8"