diff --git a/tests/altair_theme_test.py b/tests/altair_theme_test.py
index e7c43d274..67071bfd9 100644
--- a/tests/altair_theme_test.py
+++ b/tests/altair_theme_test.py
@@ -224,7 +224,7 @@ def alt_theme_test() -> alt.VConcatChart:
       el.setAttribute("class", "view");
       container.appendChild(el);
       vegaEmbed(el, spec, {
-          config: theme,
+          theme: themeName,
           defaultStyle: true,
           mode: "vega-lite"
       });