diff --git a/js/basemap_selector.ts b/js/basemap_selector.ts
index 9199c4cb1f..6f38f0a66e 100644
--- a/js/basemap_selector.ts
+++ b/js/basemap_selector.ts
@@ -16,7 +16,7 @@ export class BasemapSelector extends LitWidget<
     BasemapSelectorModel,
     BasemapSelector
 > {
-    static get componentName() {
+    static get componentName(): string {
         return `basemap-selector`;
     }