diff --git a/jupyter_events/validators.py b/jupyter_events/validators.py
index 72881ef..bd7a161 100644
--- a/jupyter_events/validators.py
+++ b/jupyter_events/validators.py
@@ -61,7 +61,7 @@ def validate_schema(schema: dict[str, Any]) -> None:
     try:
         # If the `version` attribute is an integer, coerce to string.
         # TODO: remove this in a future version.
-        if "version" in schema and type(schema["version"]) == int:
+        if "version" in schema and isinstance(schema["version"], int):
             schema["version"] = str(schema["version"])
             msg = (
                 "The `version` property of an event schema must be a string. "
@@ -69,7 +69,7 @@ def validate_schema(schema: dict[str, Any]) -> None:
                 "library, it will fail to validate. Please update schema: "
                 f"{schema['$id']}"
             )
-            warnings.warn(JupyterEventsVersionWarning(msg))
+            warnings.warn(JupyterEventsVersionWarning(msg), stacklevel=2)
         # Validate the schema against Jupyter Events metaschema.
         JUPYTER_EVENTS_SCHEMA_VALIDATOR.validate(schema)
     except ValidationError as err: