diff --git a/pyproject.toml b/pyproject.toml
index bc9cdf220..f01a562bd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -56,7 +56,7 @@ Source = "https://github.com/vega/altair"
 [project.optional-dependencies]
 all = [
     "vega_datasets>=0.9.0",
-    "vl-convert-python>=1.6.0",
+    "vl-convert-python>=1.7.0",
     "pandas>=0.25.3",
     "numpy",
     "pyarrow>=11",
@@ -431,7 +431,6 @@ module = [
     "vega_datasets.*",
     "pyarrow.*",
     "yaml.*",
-    "vl_convert.*",
     "pandas.lib.*",
     "geopandas.*",
     "nbformat.*",
diff --git a/tools/generate_schema_wrapper.py b/tools/generate_schema_wrapper.py
index c23789b72..f25affed8 100644
--- a/tools/generate_schema_wrapper.py
+++ b/tools/generate_schema_wrapper.py
@@ -54,6 +54,7 @@
 
 if TYPE_CHECKING:
     from tools.schemapi.codegen import ArgInfo, AttrGetter
+    from vl_convert import VegaThemes
 
 T = TypeVar("T", bound="str | Iterable[str]")
 
@@ -499,8 +500,8 @@ def download_schemafile(
 
 
 def _vega_lite_props_only(
-    themes: dict[str, dict[str, Any]], props: SchemaProperties, /
-) -> Iterator[tuple[str, dict[str, Any]]]:
+    themes: dict[VegaThemes, dict[str, Any]], props: SchemaProperties, /
+) -> Iterator[tuple[VegaThemes, dict[str, Any]]]:
     """Removes properties that are allowed in `Vega` but not `Vega-Lite` from theme definitions."""
     keep = props.keys()
     for name, theme_spec in themes.items():