diff --git a/pyproject.toml b/pyproject.toml
index 497eecd8..9135e9ee 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -48,7 +48,7 @@ Repository = "https://github.com/orbcorp/orb-python"
 managed = true
 # version pins are in requirements-dev.lock
 dev-dependencies = [
-    "pyright",
+    "pyright>=1.1.359",
     "mypy",
     "respx",
     "pytest",
diff --git a/requirements-dev.lock b/requirements-dev.lock
index 8cd3a6da..25dc0a41 100644
--- a/requirements-dev.lock
+++ b/requirements-dev.lock
@@ -63,7 +63,7 @@ pydantic==2.4.2
     # via orb-billing
 pydantic-core==2.10.1
     # via pydantic
-pyright==1.1.353
+pyright==1.1.359
 pytest==7.1.1
     # via pytest-asyncio
 pytest-asyncio==0.21.1
diff --git a/src/orb/_models.py b/src/orb/_models.py
index ff93fbd8..ff3f54e2 100644
--- a/src/orb/_models.py
+++ b/src/orb/_models.py
@@ -378,7 +378,7 @@ def construct_type(*, value: object, type_: object) -> object:
 
     # unwrap `Annotated[T, ...]` -> `T`
     if is_annotated_type(type_):
-        meta = get_args(type_)[1:]
+        meta: tuple[Any, ...] = get_args(type_)[1:]
         type_ = extract_type_arg(type_, 0)
     else:
         meta = tuple()
diff --git a/src/orb/_utils/_utils.py b/src/orb/_utils/_utils.py
index fd3a8a4d..17904ce6 100644
--- a/src/orb/_utils/_utils.py
+++ b/src/orb/_utils/_utils.py
@@ -265,6 +265,8 @@ def wrapper(*args: object, **kwargs: object) -> object:
                     )
                     msg = f"Missing required arguments; Expected either {variations} arguments to be given"
                 else:
+                    assert len(variants) > 0
+
                     # TODO: this error message is not deterministic
                     missing = list(set(variants[0]) - given_params)
                     if len(missing) > 1: