diff --git a/components/script/dom/response.rs b/components/script/dom/response.rs
index 1f82ba255ce..258247fb2d9 100644
--- a/components/script/dom/response.rs
+++ b/components/script/dom/response.rs
@@ -446,7 +446,7 @@ impl Response {
 
     pub fn stream_chunk(&self, chunk: Vec<u8>, can_gc: CanGc) {
         // Note, are these two actually mutually exclusive?
-        if let Some(stream_consumer) = self.stream_consumer.borrow_mut().as_ref() {
+        if let Some(stream_consumer) = self.stream_consumer.borrow().as_ref() {
             stream_consumer.consume_chunk(chunk.as_slice());
         } else if let Some(body) = self.body_stream.get() {
             body.enqueue_native(chunk, can_gc);