diff --git a/packages/theme/src/cli/polyfills/promiseWithResolvers.ts b/packages/theme/src/cli/polyfills/promiseWithResolvers.ts
index 65c607197a..f958bf4634 100644
--- a/packages/theme/src/cli/polyfills/promiseWithResolvers.ts
+++ b/packages/theme/src/cli/polyfills/promiseWithResolvers.ts
@@ -6,7 +6,7 @@ interface PromiseWithResolvers<T> {
 
 declare global {
   interface PromiseConstructor {
-    withResolvers?<T>(): PromiseWithResolvers<T>
+    withResolvers<T>(): PromiseWithResolvers<T>
   }
 }