diff --git a/pyproject.toml b/pyproject.toml
index 38f2b24..2006584 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -32,6 +32,7 @@ distribution = true
 
 [tool.pytest.ini_options]
 testpaths = ["tests"]
+markers = ["slow: slow tests (dummy.capnp, generics, interface)"]
 
 [tool.setuptools.packages.find]
 where = ["src"]
diff --git a/tests/.gitignore b/tests/.gitignore
new file mode 100644
index 0000000..b946016
--- /dev/null
+++ b/tests/.gitignore
@@ -0,0 +1 @@
+*_capnp.pyi
diff --git a/tests/schemas/test_stubs.py b/tests/schemas/test_stubs.py
new file mode 100644
index 0000000..a8b1f99
--- /dev/null
+++ b/tests/schemas/test_stubs.py
@@ -0,0 +1,70 @@
+"""Verify generated .pyi stubs are consistent with pycapnp runtime.
+
+Test file lives alongside the ``.capnp`` schemas + generated ``.pyi``
+stubs.  pycapnp's import hook handles runtime loading.
+basedpyright type-checks this file together with the project.
+"""
+
+from __future__ import annotations
+
+import sys
+from pathlib import Path
+
+# Ensure this directory is importable
+_HERE = Path(__file__).parent
+if str(_HERE) not in sys.path:
+    sys.path.insert(0, str(_HERE))
+
+import capnp  # pyright: ignore[reportMissingTypeStubs, reportUnusedImport]  # activates import hook
+import test_simple_capnp
+
+
+class TestSimpleStub:
+    """test_simple.capnp — basic struct."""
+
+    def test_new_message(self) -> None:
+        p = test_simple_capnp.Person.new_message(
+            name="Alice", age=30, email="alice@example.com"
+        )
+        assert p.name == "Alice"
+        assert p.age == 30
+
+    def test_field_assignment(self) -> None:
+        p = test_simple_capnp.Person.new_message()
+        p.name = "Bob"
+        p.age = 25
+        assert p.name == "Bob"
+
+    def test_to_dict(self) -> None:
+        p = test_simple_capnp.Person.new_message(name="Carol", age=28)
+        d = p.to_dict()
+        assert d["name"] == "Carol"
+
+    def test_from_dict(self) -> None:
+        p = test_simple_capnp.Person.new_message()
+        _ = p.from_dict({"name": "Dave", "age": 35})
+        assert p.name == "Dave"
+
+    def test_serialize_roundtrip(self) -> None:
+        p = test_simple_capnp.Person.new_message(name="Eve", age=22)
+        data = p.to_bytes()
+        p2 = test_simple_capnp.Person.from_bytes(data)
+        assert p2 is not None
+
+
+class TestNestedStub:
+    """test_nested.capnp — nested types + lists."""
+
+    def test_nested_message(self) -> None:
+        import test_nested_capnp
+        ab = test_nested_capnp.AddressBook.new_message()
+        assert ab.people is not None
+
+
+class TestGenericsStub:
+    """test_generics.capnp — generic structs."""
+
+    def test_holder_loads(self) -> None:
+        import test_generics_capnp
+        c = test_generics_capnp.Container.new_message()
+        assert c is not None
diff --git a/tests/test_models.py b/tests/test_models.py
index d15e5b6..937469e 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -85,11 +85,11 @@ class TestTypeRegistry:
         assert reg.get_or_raise(1) is info
         import pytest
         with pytest.raises(KeyError):
-            reg.get_or_raise(999)
+            _ = reg.get_or_raise(999)
 
     def test_contains(self):
         reg = TypeRegistry()
-        info = TypeInfo(1, "Foo", "Foo", {}, None, "struct")
+        info: TypeInfo = TypeInfo(1, "Foo", "Foo", {}, None, "struct")
         reg.register(info)
         assert 1 in reg
         assert 2 not in reg
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 4f779bf..5f96cde 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -1,6 +1,5 @@
 """Tests for capnp_stubgen.utils."""
 
-import pytest
 from capnp_stubgen.utils import (
     filename_to_module_name,
     get_display_name,