diff --git a/.gitignore b/.gitignore
index 1093e258..62c025a0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -26,6 +26,7 @@ wheels/
 *.egg
 MANIFEST
 version.txt
+pip-wheel-metadata
 
 # Installer logs
 pip-log.txt
diff --git a/src/syrupy/__init__.py b/src/syrupy/__init__.py
index 784f6aaa..2f85926a 100644
--- a/src/syrupy/__init__.py
+++ b/src/syrupy/__init__.py
@@ -109,12 +109,15 @@ def pytest_sessionstart(session: Any) -> None:
     config._syrupy.start()
 
 
-def pytest_collection_modifyitems(session: Any, config: Any, items: List[Any]) -> None:
+def pytest_collection_modifyitems(
+    session: Any, config: Any, items: List["pytest.Item"]
+) -> None:
     """
     After tests are collected and before any modification is performed.
     https://docs.pytest.org/en/latest/reference.html#_pytest.hookspec.pytest_collection_modifyitems
     """
-    config._syrupy._all_items.update(items)
+    for item in config._syrupy.filter_valid_items(items):
+        config._syrupy._all_items[item] = True
 
 
 def pytest_collection_finish(session: Any) -> None:
@@ -122,7 +125,8 @@ def pytest_collection_finish(session: Any) -> None:
     After collection has been performed and modified.
     https://docs.pytest.org/en/latest/reference.html#_pytest.hookspec.pytest_collection_finish
     """
-    session.config._syrupy._ran_items.update(session.items)
+    for item in session.config._syrupy.filter_valid_items(session.items):
+        session.config._syrupy._ran_items[item] = True
 
 
 def pytest_sessionfinish(session: Any, exitstatus: int) -> None:
diff --git a/src/syrupy/report.py b/src/syrupy/report.py
index 859d07e5..2e750578 100644
--- a/src/syrupy/report.py
+++ b/src/syrupy/report.py
@@ -5,13 +5,13 @@
 from pathlib import Path
 from typing import (
     TYPE_CHECKING,
-    Any,
+    Dict,
     Iterator,
     List,
-    Set,
 )
 
 import attr
+import pytest
 
 from .data import (
     Snapshot,
@@ -36,8 +36,8 @@
 @attr.s
 class SnapshotReport:
     base_dir: str = attr.ib()
-    all_items: Set[Any] = attr.ib()
-    ran_items: Set[Any] = attr.ib()
+    all_items: Dict["pytest.Item", bool] = attr.ib()
+    ran_items: Dict["pytest.Item", bool] = attr.ib()
     update_snapshots: bool = attr.ib()
     is_providing_paths: bool = attr.ib()
     is_providing_nodes: bool = attr.ib()
diff --git a/src/syrupy/session.py b/src/syrupy/session.py
index db868869..6c33b919 100644
--- a/src/syrupy/session.py
+++ b/src/syrupy/session.py
@@ -1,14 +1,14 @@
 from pathlib import Path
 from typing import (
     TYPE_CHECKING,
-    Any,
     Dict,
+    Iterable,
     List,
     Optional,
-    Set,
 )
 
 import attr
+import pytest
 
 from .constants import EXIT_STATUS_FAIL_UNUSED
 from .data import SnapshotFossils
@@ -28,15 +28,15 @@ class SnapshotSession:
     is_providing_paths: bool = attr.ib()
     is_providing_nodes: bool = attr.ib()
     report: Optional["SnapshotReport"] = attr.ib(default=None)
-    _all_items: Set[Any] = attr.ib(factory=set)
-    _ran_items: Set[Any] = attr.ib(factory=set)
+    _all_items: Dict["pytest.Item", bool] = attr.ib(factory=dict)
+    _ran_items: Dict["pytest.Item", bool] = attr.ib(factory=dict)
     _assertions: List["SnapshotAssertion"] = attr.ib(factory=list)
     _extensions: Dict[str, "AbstractSyrupyExtension"] = attr.ib(factory=dict)
 
     def start(self) -> None:
         self.report = None
-        self._all_items = set()
-        self._ran_items = set()
+        self._all_items = {}
+        self._ran_items = {}
         self._assertions = []
         self._extensions = {}
 
@@ -89,3 +89,7 @@ def remove_unused_snapshots(
                 )
             elif snapshot_location not in used_snapshot_fossils:
                 Path(snapshot_location).unlink()
+
+    @staticmethod
+    def filter_valid_items(items: List["pytest.Item"]) -> Iterable["pytest.Item"]:
+        return (item for item in items if isinstance(item, pytest.Function))
diff --git a/stubs/pytest.pyi b/stubs/pytest.pyi
index 3dea19db..888b02b3 100644
--- a/stubs/pytest.pyi
+++ b/stubs/pytest.pyi
@@ -3,3 +3,6 @@ from typing import Any, Callable, TypeVar
 ReturnType = TypeVar("ReturnType")
 
 def fixture(func: Callable[..., ReturnType]) -> Callable[..., ReturnType]: ...
+
+class Function: ...
+class Item: ...
diff --git a/tests/test_integration_pytest_extension.py b/tests/test_integration_pytest_extension.py
new file mode 100644
index 00000000..fced0a75
--- /dev/null
+++ b/tests/test_integration_pytest_extension.py
@@ -0,0 +1,28 @@
+from .utils import clean_output
+
+
+def test_ignores_non_function_nodes(testdir):
+    conftest = """
+        import pytest
+
+        class CustomItem(pytest.Item, pytest.File):
+            def __init__(self, *args, **kwargs):
+                super().__init__(*args, **kwargs)
+                self._nodeid += "::CUSTOM"
+
+            def runtest(self):
+                pass
+
+        def pytest_collect_file(path, parent):
+            return CustomItem(path, parent)
+        """
+    testcase = """
+        def test_example(snapshot):
+            assert snapshot == 1
+        """
+    testdir.makepyfile(conftest=conftest)
+    testdir.makepyfile(test_file=testcase)
+    result = testdir.runpytest("test_file.py", "-v", "--snapshot-update")
+    result_stdout = clean_output(result.stdout.str())
+    assert result.ret == 0
+    assert "test_file.py::CUSTOM" in result_stdout