diff --git a/.changeset/famous-glasses-clean.md b/.changeset/famous-glasses-clean.md
new file mode 100644
index 00000000000..b5749f54a24
--- /dev/null
+++ b/.changeset/famous-glasses-clean.md
@@ -0,0 +1,7 @@
+---
+'@astrojs/starlight': patch
+---
+
+Safely handle Zod errors 
+
+Prevents bugs where errors without the `.received` props would through and cause builds to fail unnecessarily.
diff --git a/packages/starlight/utils/error-map.ts b/packages/starlight/utils/error-map.ts
index 667a91af365..b00ed45b3fd 100644
--- a/packages/starlight/utils/error-map.ts
+++ b/packages/starlight/utils/error-map.ts
@@ -143,7 +143,7 @@ const errorMap: z.ZodErrorMap = (baseError, ctx) => {
 };
 
 const getTypeOrLiteralMsg = (error: TypeOrLiteralErrByPathEntry): string => {
-	if (error.received === 'undefined') return 'Required';
+	if (typeof error.received === 'undefined') return 'Required';
 	const expectedDeduped = new Set(error.expected);
 	switch (error.code) {
 		case 'invalid_type':