diff --git a/components/script/body.rs b/components/script/body.rs
index 6e2e7359fbc..2c84fdd6495 100644
--- a/components/script/body.rs
+++ b/components/script/body.rs
@@ -438,21 +438,21 @@ impl ExtractedBody {
 
 /// <https://fetch.spec.whatwg.org/#concept-bodyinit-extract>
 pub trait Extractable {
-    fn extract(&self, global: &GlobalScope) -> Fallible<ExtractedBody>;
+    fn extract(&self, global: &GlobalScope, can_gc: CanGc) -> Fallible<ExtractedBody>;
 }
 
 impl Extractable for BodyInit {
     // https://fetch.spec.whatwg.org/#concept-bodyinit-extract
-    fn extract(&self, global: &GlobalScope) -> Fallible<ExtractedBody> {
+    fn extract(&self, global: &GlobalScope, can_gc: CanGc) -> Fallible<ExtractedBody> {
         match self {
-            BodyInit::String(ref s) => s.extract(global),
-            BodyInit::URLSearchParams(ref usp) => usp.extract(global),
-            BodyInit::Blob(ref b) => b.extract(global),
-            BodyInit::FormData(ref formdata) => formdata.extract(global),
+            BodyInit::String(ref s) => s.extract(global, can_gc),
+            BodyInit::URLSearchParams(ref usp) => usp.extract(global, can_gc),
+            BodyInit::Blob(ref b) => b.extract(global, can_gc),
+            BodyInit::FormData(ref formdata) => formdata.extract(global, can_gc),
             BodyInit::ArrayBuffer(ref typedarray) => {
                 let bytes = typedarray.to_vec();
                 let total_bytes = bytes.len();
-                let stream = ReadableStream::new_from_bytes(global, bytes);
+                let stream = ReadableStream::new_from_bytes(global, bytes, can_gc);
                 Ok(ExtractedBody {
                     stream,
                     total_bytes: Some(total_bytes),
@@ -463,7 +463,7 @@ impl Extractable for BodyInit {
             BodyInit::ArrayBufferView(ref typedarray) => {
                 let bytes = typedarray.to_vec();
                 let total_bytes = bytes.len();
-                let stream = ReadableStream::new_from_bytes(global, bytes);
+                let stream = ReadableStream::new_from_bytes(global, bytes, can_gc);
                 Ok(ExtractedBody {
                     stream,
                     total_bytes: Some(total_bytes),
@@ -493,10 +493,10 @@ impl Extractable for BodyInit {
 }
 
 impl Extractable for Vec<u8> {
-    fn extract(&self, global: &GlobalScope) -> Fallible<ExtractedBody> {
+    fn extract(&self, global: &GlobalScope, can_gc: CanGc) -> Fallible<ExtractedBody> {
         let bytes = self.clone();
         let total_bytes = self.len();
-        let stream = ReadableStream::new_from_bytes(global, bytes);
+        let stream = ReadableStream::new_from_bytes(global, bytes, can_gc);
         Ok(ExtractedBody {
             stream,
             total_bytes: Some(total_bytes),
@@ -508,7 +508,7 @@ impl Extractable for Vec<u8> {
 }
 
 impl Extractable for Blob {
-    fn extract(&self, _global: &GlobalScope) -> Fallible<ExtractedBody> {
+    fn extract(&self, _global: &GlobalScope, can_gc: CanGc) -> Fallible<ExtractedBody> {
         let blob_type = self.Type();
         let content_type = if blob_type.as_ref().is_empty() {
             None
@@ -517,7 +517,7 @@ impl Extractable for Blob {
         };
         let total_bytes = self.Size() as usize;
         Ok(ExtractedBody {
-            stream: self.get_stream(),
+            stream: self.get_stream(can_gc),
             total_bytes: Some(total_bytes),
             content_type,
             source: BodySource::Object,
@@ -526,11 +526,11 @@ impl Extractable for Blob {
 }
 
 impl Extractable for DOMString {
-    fn extract(&self, global: &GlobalScope) -> Fallible<ExtractedBody> {
+    fn extract(&self, global: &GlobalScope, can_gc: CanGc) -> Fallible<ExtractedBody> {
         let bytes = self.as_bytes().to_owned();
         let total_bytes = bytes.len();
         let content_type = Some(DOMString::from("text/plain;charset=UTF-8"));
-        let stream = ReadableStream::new_from_bytes(global, bytes);
+        let stream = ReadableStream::new_from_bytes(global, bytes, can_gc);
         Ok(ExtractedBody {
             stream,
             total_bytes: Some(total_bytes),
@@ -541,7 +541,7 @@ impl Extractable for DOMString {
 }
 
 impl Extractable for FormData {
-    fn extract(&self, global: &GlobalScope) -> Fallible<ExtractedBody> {
+    fn extract(&self, global: &GlobalScope, can_gc: CanGc) -> Fallible<ExtractedBody> {
         let boundary = generate_boundary();
         let bytes = encode_multipart_form_data(&mut self.datums(), boundary.clone(), UTF_8);
         let total_bytes = bytes.len();
@@ -549,7 +549,7 @@ impl Extractable for FormData {
             "multipart/form-data;boundary={}",
             boundary
         )));
-        let stream = ReadableStream::new_from_bytes(global, bytes);
+        let stream = ReadableStream::new_from_bytes(global, bytes, can_gc);
         Ok(ExtractedBody {
             stream,
             total_bytes: Some(total_bytes),
@@ -560,13 +560,13 @@ impl Extractable for FormData {
 }
 
 impl Extractable for URLSearchParams {
-    fn extract(&self, global: &GlobalScope) -> Fallible<ExtractedBody> {
+    fn extract(&self, global: &GlobalScope, can_gc: CanGc) -> Fallible<ExtractedBody> {
         let bytes = self.serialize_utf8().into_bytes();
         let total_bytes = bytes.len();
         let content_type = Some(DOMString::from(
             "application/x-www-form-urlencoded;charset=UTF-8",
         ));
-        let stream = ReadableStream::new_from_bytes(global, bytes);
+        let stream = ReadableStream::new_from_bytes(global, bytes, can_gc);
         Ok(ExtractedBody {
             stream,
             total_bytes: Some(total_bytes),
@@ -756,7 +756,7 @@ fn consume_body_with_promise<T: BodyMixin + DomObject>(
     // Step 2.
     let stream = match object.body() {
         Some(stream) => stream,
-        None => ReadableStream::new_from_bytes(&global, Vec::with_capacity(0)),
+        None => ReadableStream::new_from_bytes(&global, Vec::with_capacity(0), can_gc),
     };
 
     // Step 3.
diff --git a/components/script/dom/bindings/codegen/Bindings.conf b/components/script/dom/bindings/codegen/Bindings.conf
index a2c216863f7..de0f67315d1 100644
--- a/components/script/dom/bindings/codegen/Bindings.conf
+++ b/components/script/dom/bindings/codegen/Bindings.conf
@@ -30,7 +30,7 @@ DOMInterfaces = {
 
 'Blob': {
     'weakReferenceable': True,
-    'canGc': ['Slice', 'Text', 'ArrayBuffer'], 
+    'canGc': ['Slice', 'Text', 'ArrayBuffer', 'Stream'],
 },
 
 'Bluetooth': {
diff --git a/components/script/dom/blob.rs b/components/script/dom/blob.rs
index 310a531a7da..31c6fa64620 100644
--- a/components/script/dom/blob.rs
+++ b/components/script/dom/blob.rs
@@ -86,8 +86,8 @@ impl Blob {
     }
 
     /// <https://w3c.github.io/FileAPI/#blob-get-stream>
-    pub fn get_stream(&self) -> DomRoot<ReadableStream> {
-        self.global().get_blob_stream(&self.blob_id)
+    pub fn get_stream(&self, can_gc: CanGc) -> DomRoot<ReadableStream> {
+        self.global().get_blob_stream(&self.blob_id, can_gc)
     }
 }
 
@@ -237,8 +237,8 @@ impl BlobMethods for Blob {
     }
 
     // <https://w3c.github.io/FileAPI/#blob-get-stream>
-    fn Stream(&self, _cx: JSContext) -> NonNull<JSObject> {
-        self.get_stream().get_js_stream()
+    fn Stream(&self, _cx: JSContext, can_gc: CanGc) -> NonNull<JSObject> {
+        self.get_stream(can_gc).get_js_stream()
     }
 
     // https://w3c.github.io/FileAPI/#slice-method-algo
diff --git a/components/script/dom/globalscope.rs b/components/script/dom/globalscope.rs
index a972c7d7eb1..f7641d0bd15 100644
--- a/components/script/dom/globalscope.rs
+++ b/components/script/dom/globalscope.rs
@@ -617,10 +617,10 @@ impl MessageListener {
 }
 
 /// Callback used to enqueue file chunks to streams as part of FileListener.
-fn stream_handle_incoming(stream: &ReadableStream, bytes: Fallible<Vec<u8>>) {
+fn stream_handle_incoming(stream: &ReadableStream, bytes: Fallible<Vec<u8>>, can_gc: CanGc) {
     match bytes {
         Ok(b) => {
-            stream.enqueue_native(b);
+            stream.enqueue_native(b, can_gc);
         },
         Err(e) => {
             stream.error_native(e);
@@ -643,7 +643,7 @@ impl FileListener {
 
                         let task = task!(enqueue_stream_chunk: move || {
                             let stream = trusted.root();
-                            stream_handle_incoming(&stream, Ok(blob_buf.bytes));
+                            stream_handle_incoming(&stream, Ok(blob_buf.bytes), CanGc::note());
                         });
 
                         let _ = self
@@ -667,7 +667,7 @@ impl FileListener {
 
                         let task = task!(enqueue_stream_chunk: move || {
                             let stream = trusted.root();
-                            stream_handle_incoming(&stream, Ok(bytes_in));
+                            stream_handle_incoming(&stream, Ok(bytes_in), CanGc::note());
                         });
 
                         let _ = self
@@ -733,7 +733,7 @@ impl FileListener {
                             let _ = self.task_source.queue_with_canceller(
                                 task!(error_stream: move || {
                                     let stream = trusted_stream.root();
-                                    stream_handle_incoming(&stream, error);
+                                    stream_handle_incoming(&stream, error, CanGc::note());
                                 }),
                                 &self.task_canceller,
                             );
@@ -1988,11 +1988,11 @@ impl GlobalScope {
     }
 
     /// <https://w3c.github.io/FileAPI/#blob-get-stream>
-    pub fn get_blob_stream(&self, blob_id: &BlobId) -> DomRoot<ReadableStream> {
+    pub fn get_blob_stream(&self, blob_id: &BlobId, can_gc: CanGc) -> DomRoot<ReadableStream> {
         let (file_id, size) = match self.get_blob_bytes_or_file_id(blob_id) {
             BlobResult::Bytes(bytes) => {
                 // If we have all the bytes in memory, queue them and close the stream.
-                let stream = ReadableStream::new_from_bytes(self, bytes);
+                let stream = ReadableStream::new_from_bytes(self, bytes, can_gc);
                 return stream;
             },
             BlobResult::File(id, size) => (id, size),
diff --git a/components/script/dom/htmlformelement.rs b/components/script/dom/htmlformelement.rs
index 50a70675ba4..53a38441b11 100644
--- a/components/script/dom/htmlformelement.rs
+++ b/components/script/dom/htmlformelement.rs
@@ -870,6 +870,7 @@ impl HTMLFormElement {
                     enctype,
                     encoding,
                     target_window,
+                    can_gc,
                 );
             },
             // https://html.spec.whatwg.org/multipage/#submit-get-action
@@ -920,6 +921,7 @@ impl HTMLFormElement {
         enctype: FormEncType,
         encoding: &'static Encoding,
         target: &Window,
+        can_gc: CanGc,
     ) {
         let boundary = generate_boundary();
         let bytes = match enctype {
@@ -957,7 +959,7 @@ impl HTMLFormElement {
         let global = self.global();
 
         let request_body = bytes
-            .extract(&global)
+            .extract(&global, can_gc)
             .expect("Couldn't extract body.")
             .into_net_request_body()
             .0;
diff --git a/components/script/dom/readablestream.rs b/components/script/dom/readablestream.rs
index 24272757071..76c81d2ed14 100644
--- a/components/script/dom/readablestream.rs
+++ b/components/script/dom/readablestream.rs
@@ -34,7 +34,7 @@ use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
 use crate::js::conversions::FromJSValConvertible;
 use crate::realms::{enter_realm, InRealm};
-use crate::script_runtime::JSContext as SafeJSContext;
+use crate::script_runtime::{CanGc, JSContext as SafeJSContext};
 
 static UNDERLYING_SOURCE_TRAPS: ReadableStreamUnderlyingSourceTraps =
     ReadableStreamUnderlyingSourceTraps {
@@ -101,12 +101,16 @@ impl ReadableStream {
     }
 
     /// Build a stream backed by a Rust source that has already been read into memory.
-    pub fn new_from_bytes(global: &GlobalScope, bytes: Vec<u8>) -> DomRoot<ReadableStream> {
+    pub fn new_from_bytes(
+        global: &GlobalScope,
+        bytes: Vec<u8>,
+        can_gc: CanGc,
+    ) -> DomRoot<ReadableStream> {
         let stream = ReadableStream::new_with_external_underlying_source(
             global,
             ExternalUnderlyingSource::Memory(bytes.len()),
         );
-        stream.enqueue_native(bytes);
+        stream.enqueue_native(bytes, can_gc);
         stream.close_native();
         stream
     }
@@ -153,7 +157,7 @@ impl ReadableStream {
     }
 
     #[allow(unsafe_code)]
-    pub fn enqueue_native(&self, bytes: Vec<u8>) {
+    pub fn enqueue_native(&self, bytes: Vec<u8>, can_gc: CanGc) {
         let global = self.global();
         let _ar = enter_realm(&*global);
         let cx = GlobalScope::get_cx();
@@ -163,7 +167,7 @@ impl ReadableStream {
         self.external_underlying_source
             .as_ref()
             .expect("No external source to enqueue bytes.")
-            .enqueue_chunk(cx, handle, bytes);
+            .enqueue_chunk(cx, handle, bytes, can_gc);
     }
 
     #[allow(unsafe_code)]
@@ -324,7 +328,12 @@ unsafe extern "C" fn request_data(
     desired_size: usize,
 ) {
     let source = &*(source as *const ExternalUnderlyingSourceController);
-    source.pull(SafeJSContext::from_ptr(cx), stream, desired_size);
+    source.pull(
+        SafeJSContext::from_ptr(cx),
+        stream,
+        desired_size,
+        CanGc::note(),
+    );
 }
 
 #[allow(unsafe_code)]
@@ -427,12 +436,15 @@ impl ExternalUnderlyingSourceController {
     }
 
     /// Signal available bytes if the stream is currently readable.
+    /// The apparently unused CanGc argument represents that the JS API calls like
+    /// `ReadableStreamUpdateDataAvailableFromSource` can trigger a GC.
     #[allow(unsafe_code)]
     fn maybe_signal_available_bytes(
         &self,
         cx: SafeJSContext,
         stream: HandleObject,
         available: usize,
+        _can_gc: CanGc,
     ) {
         if available == 0 {
             return;
@@ -467,17 +479,23 @@ impl ExternalUnderlyingSourceController {
         self.maybe_close_js_stream(cx, stream);
     }
 
-    fn enqueue_chunk(&self, cx: SafeJSContext, stream: HandleObject, mut chunk: Vec<u8>) {
+    fn enqueue_chunk(
+        &self,
+        cx: SafeJSContext,
+        stream: HandleObject,
+        mut chunk: Vec<u8>,
+        can_gc: CanGc,
+    ) {
         let available = {
             let mut buffer = self.buffer.borrow_mut();
             buffer.append(&mut chunk);
             buffer.len()
         };
-        self.maybe_signal_available_bytes(cx, stream, available);
+        self.maybe_signal_available_bytes(cx, stream, available, can_gc);
     }
 
     #[allow(unsafe_code)]
-    fn pull(&self, cx: SafeJSContext, stream: HandleObject, _desired_size: usize) {
+    fn pull(&self, cx: SafeJSContext, stream: HandleObject, _desired_size: usize, can_gc: CanGc) {
         // Note: for pull sources,
         // this would be the time to ask for a chunk.
 
@@ -490,7 +508,7 @@ impl ExternalUnderlyingSourceController {
             buffer.len()
         };
 
-        self.maybe_signal_available_bytes(cx, stream, available);
+        self.maybe_signal_available_bytes(cx, stream, available, can_gc);
     }
 
     fn get_chunk_with_length(&self, length: usize) -> Vec<u8> {
diff --git a/components/script/dom/request.rs b/components/script/dom/request.rs
index cf4eda5d2c2..61f1f408260 100644
--- a/components/script/dom/request.rs
+++ b/components/script/dom/request.rs
@@ -477,7 +477,7 @@ impl RequestMethods for Request {
             // Step 37.1 TODO "If init["keepalive"] exists and is true..."
 
             // Step 37.2
-            let mut extracted_body = init_body.extract(global)?;
+            let mut extracted_body = init_body.extract(global, can_gc)?;
 
             // Step 37.3
             if let Some(contents) = extracted_body.content_type.take() {
diff --git a/components/script/dom/response.rs b/components/script/dom/response.rs
index 92a04fe796c..1f82ba255ce 100644
--- a/components/script/dom/response.rs
+++ b/components/script/dom/response.rs
@@ -190,7 +190,7 @@ impl ResponseMethods for Response {
                 total_bytes: _,
                 content_type,
                 source: _,
-            } = body.extract(global)?;
+            } = body.extract(global, can_gc)?;
 
             r.body_stream.set(Some(&*stream));
 
@@ -210,7 +210,7 @@ impl ResponseMethods for Response {
         } else {
             // Reset FetchResponse to an in-memory stream with empty byte sequence here for
             // no-init-body case
-            let stream = ReadableStream::new_from_bytes(global, Vec::with_capacity(0));
+            let stream = ReadableStream::new_from_bytes(global, Vec::with_capacity(0), can_gc);
             r.body_stream.set(Some(&*stream));
         }
 
@@ -444,12 +444,12 @@ impl Response {
         *self.stream_consumer.borrow_mut() = sc;
     }
 
-    pub fn stream_chunk(&self, chunk: Vec<u8>) {
+    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() {
             stream_consumer.consume_chunk(chunk.as_slice());
         } else if let Some(body) = self.body_stream.get() {
-            body.enqueue_native(chunk);
+            body.enqueue_native(chunk, can_gc);
         }
     }
 
diff --git a/components/script/dom/xmlhttprequest.rs b/components/script/dom/xmlhttprequest.rs
index b9cc481087c..970012c12e9 100644
--- a/components/script/dom/xmlhttprequest.rs
+++ b/components/script/dom/xmlhttprequest.rs
@@ -576,7 +576,7 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
                 };
                 let total_bytes = bytes.len();
                 let global = self.global();
-                let stream = ReadableStream::new_from_bytes(&global, bytes);
+                let stream = ReadableStream::new_from_bytes(&global, bytes, can_gc);
                 Some(ExtractedBody {
                     stream,
                     total_bytes: Some(total_bytes),
@@ -585,7 +585,9 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
                 })
             },
             Some(DocumentOrXMLHttpRequestBodyInit::Blob(ref b)) => {
-                let extracted_body = b.extract(&self.global()).expect("Couldn't extract body.");
+                let extracted_body = b
+                    .extract(&self.global(), can_gc)
+                    .expect("Couldn't extract body.");
                 if !extracted_body.in_memory() && self.sync.get() {
                     warn!("Sync XHR with not in-memory Blob as body not supported");
                     None
@@ -595,22 +597,23 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
             },
             Some(DocumentOrXMLHttpRequestBodyInit::FormData(ref formdata)) => Some(
                 formdata
-                    .extract(&self.global())
+                    .extract(&self.global(), can_gc)
+                    .expect("Couldn't extract body."),
+            ),
+            Some(DocumentOrXMLHttpRequestBodyInit::String(ref str)) => Some(
+                str.extract(&self.global(), can_gc)
                     .expect("Couldn't extract body."),
             ),
-            Some(DocumentOrXMLHttpRequestBodyInit::String(ref str)) => {
-                Some(str.extract(&self.global()).expect("Couldn't extract body."))
-            },
             Some(DocumentOrXMLHttpRequestBodyInit::URLSearchParams(ref urlsp)) => Some(
                 urlsp
-                    .extract(&self.global())
+                    .extract(&self.global(), can_gc)
                     .expect("Couldn't extract body."),
             ),
             Some(DocumentOrXMLHttpRequestBodyInit::ArrayBuffer(ref typedarray)) => {
                 let bytes = typedarray.to_vec();
                 let total_bytes = bytes.len();
                 let global = self.global();
-                let stream = ReadableStream::new_from_bytes(&global, bytes);
+                let stream = ReadableStream::new_from_bytes(&global, bytes, can_gc);
                 Some(ExtractedBody {
                     stream,
                     total_bytes: Some(total_bytes),
@@ -622,7 +625,7 @@ impl XMLHttpRequestMethods for XMLHttpRequest {
                 let bytes = typedarray.to_vec();
                 let total_bytes = bytes.len();
                 let global = self.global();
-                let stream = ReadableStream::new_from_bytes(&global, bytes);
+                let stream = ReadableStream::new_from_bytes(&global, bytes, can_gc);
                 Some(ExtractedBody {
                     stream,
                     total_bytes: Some(total_bytes),
diff --git a/components/script/fetch.rs b/components/script/fetch.rs
index 78f3f28c4f2..8d1bbf1edc8 100644
--- a/components/script/fetch.rs
+++ b/components/script/fetch.rs
@@ -277,7 +277,7 @@ impl FetchResponseListener for FetchContext {
 
     fn process_response_chunk(&mut self, _: RequestId, chunk: Vec<u8>) {
         let response = self.response_object.root();
-        response.stream_chunk(chunk);
+        response.stream_chunk(chunk, CanGc::note());
     }
 
     fn process_response_eof(