diff --git a/packages/astro/src/core/endpoint/index.ts b/packages/astro/src/core/endpoint/index.ts
index 5822685cf987..9bbfbc4cd883 100644
--- a/packages/astro/src/core/endpoint/index.ts
+++ b/packages/astro/src/core/endpoint/index.ts
@@ -78,6 +78,7 @@ export function createAPIContext({
 
 	// We define a custom property, so we can check the value passed to locals
 	Object.defineProperty(context, 'locals', {
+		enumerable: true,
 		get() {
 			return Reflect.get(request, clientLocalsSymbol);
 		},
diff --git a/packages/astro/src/core/render/context.ts b/packages/astro/src/core/render/context.ts
index eba81526e978..a43650a556cb 100644
--- a/packages/astro/src/core/render/context.ts
+++ b/packages/astro/src/core/render/context.ts
@@ -67,6 +67,7 @@ export async function createRenderContext(
 
 	// We define a custom property, so we can check the value passed to locals
 	Object.defineProperty(context, 'locals', {
+		enumerable: true,
 		get() {
 			return Reflect.get(request, clientLocalsSymbol);
 		},