diff --git a/numpyro/contrib/control_flow/cond.py b/numpyro/contrib/control_flow/cond.py
index 1931d490c..27a0dcee8 100644
--- a/numpyro/contrib/control_flow/cond.py
+++ b/numpyro/contrib/control_flow/cond.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 from functools import partial
+from typing import Any, Callable
 
 from jax import device_put, lax
 
@@ -72,7 +73,7 @@ def cond_wrapper(
     return lax.cond(pred, wrapped_true_fun, wrapped_false_fun, wrapped_operand)
 
 
-def cond(pred, true_fun, false_fun, operand):
+def cond(pred: bool, true_fun: Callable, false_fun: Callable, operand: Any) -> Any:
     """
     This primitive conditionally applies ``true_fun`` or ``false_fun``. See
     :func:`jax.lax.cond` for more information.
diff --git a/numpyro/contrib/control_flow/scan.py b/numpyro/contrib/control_flow/scan.py
index 7a2689cf1..4905ba24b 100644
--- a/numpyro/contrib/control_flow/scan.py
+++ b/numpyro/contrib/control_flow/scan.py
@@ -3,6 +3,7 @@
 
 from collections import OrderedDict
 from functools import partial
+from typing import Callable
 
 import jax
 from jax import device_put, lax, random
@@ -278,7 +279,7 @@ def scan_wrapper(
     length,
     reverse,
     rng_key=None,
-    substitute_stack=[],
+    substitute_stack=None,
     enum=False,
     history=1,
     first_available_dim=None,
@@ -339,7 +340,14 @@ def body_fn(wrapped_carry, x):
     return last_carry, (pytree_trace, ys)
 
 
-def scan(f, init, xs, length=None, reverse=False, history=1):
+def scan(
+    f: Callable,
+    init,
+    xs,
+    length: int | None = None,
+    reverse: bool = False,
+    history: int = 1,
+):
     """
     This primitive scans a function over the leading array axes of
     `xs` while carrying along state. See :func:`jax.lax.scan` for more
@@ -433,7 +441,7 @@ def g(*args, **kwargs):
     :param init: the initial carrying state
     :param xs: the values over which we scan along the leading axis. This can
         be any JAX pytree (e.g. list/dict of arrays).
-    :param length: optional value specifying the length of `xs`
+    :param int | None length: optional value specifying the length of `xs`
         but can be used when `xs` is an empty pytree (e.g. None)
     :param bool reverse: optional boolean specifying whether to run the scan iteration
         forward (the default) or in reverse
diff --git a/numpyro/infer/util.py b/numpyro/infer/util.py
index d0596c1e0..1ff0b5c5a 100644
--- a/numpyro/infer/util.py
+++ b/numpyro/infer/util.py
@@ -2,6 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 from collections import namedtuple
+from collections.abc import Sequence
 from contextlib import contextmanager
 from functools import partial
 from typing import Callable, Optional
@@ -931,7 +932,7 @@ def __init__(
         guide: Optional[Callable] = None,
         params: Optional[dict] = None,
         num_samples: Optional[int] = None,
-        return_sites: Optional[list[str]] = None,
+        return_sites: Optional[Sequence[str]] = None,
         infer_discrete: bool = False,
         parallel: bool = False,
         batch_ndims: Optional[int] = None,
diff --git a/pyproject.toml b/pyproject.toml
index c9d1668f7..847758329 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -109,7 +109,8 @@ ignore_missing_imports = true
 
 [[tool.mypy.overrides]]
 module = [
-    #"numpyro.contrib.einstein.*",
+    "numpyro.contrib.control_flow.*", # types missing
+    "numpyro.contrib.funsor.*",       # types missing
     "numpyro.contrib.hsgp.*",
 ]
 ignore_errors = false