diff --git a/cloudflare/r2object.go b/cloudflare/r2object.go
index c3fd027..d721240 100644
--- a/cloudflare/r2object.go
+++ b/cloudflare/r2object.go
@@ -82,6 +82,9 @@ type R2HTTPMetadata struct {
 }
 
 func toR2HTTPMetadata(v js.Value) (R2HTTPMetadata, error) {
+	if v.IsUndefined() || v.IsNull() {
+		return R2HTTPMetadata{}, nil
+	}
 	cacheExpiry, err := jsutil.MaybeDate(v.Get("cacheExpiry"))
 	if err != nil {
 		return R2HTTPMetadata{}, fmt.Errorf("error converting cacheExpiry: %w", err)
diff --git a/internal/jsutil/jsutil.go b/internal/jsutil/jsutil.go
index cd14c22..1175029 100644
--- a/internal/jsutil/jsutil.go
+++ b/internal/jsutil/jsutil.go
@@ -66,6 +66,9 @@ func AwaitPromise(promiseVal js.Value) (js.Value, error) {
 
 // StrRecordToMap converts JavaScript side's Record<string, string> into map[string]string.
 func StrRecordToMap(v js.Value) map[string]string {
+	if v.IsUndefined() || v.IsNull() {
+		return map[string]string{}
+	}
 	entries := ObjectClass.Call("entries", v)
 	entriesLen := entries.Get("length").Int()
 	result := make(map[string]string, entriesLen)