diff --git a/internal/readablestream/reader.go b/internal/readablestream/reader.go
index 854f6fd..1842d4d 100644
--- a/internal/readablestream/reader.go
+++ b/internal/readablestream/reader.go
@@ -14,7 +14,7 @@ type Reader struct {
 	off   int
 }
 
-var _ io.Reader = (*Reader)(nil)
+var _ io.ReadCloser = (*Reader)(nil)
 
 func NewReader(r safejs.Value) *Reader {
 	return &Reader{
@@ -83,3 +83,14 @@ func (r *Reader) Read(p []byte) (int, error) {
 
 	return n, nil
 }
+
+func (r *Reader) Close() error {
+	p, err := r.value.Call("cancel")
+	if err != nil {
+		return err
+	}
+
+	_, err = promise.Await(safejs.Unsafe(p))
+
+	return err
+}
diff --git a/request.go b/request.go
index c8e82e8..4818aa0 100644
--- a/request.go
+++ b/request.go
@@ -34,7 +34,7 @@ func Request(uvalue js.Value) (*http.Request, error) {
 		return nil, err
 	}
 
-	var bodyReader io.Reader
+	var bodyReader io.ReadCloser
 
 	if !body.IsNull() {
 		// WORKAROUND: Firefox does not have request.body ReadableStream
@@ -66,7 +66,7 @@ func Request(uvalue js.Value) (*http.Request, error) {
 	req := &http.Request{
 		Method: method,
 		URL:    u,
-		Body:   io.NopCloser(bodyReader),
+		Body:   bodyReader,
 		Header: make(http.Header),
 	}