diff --git a/components/script/dom/workerglobalscope.rs b/components/script/dom/workerglobalscope.rs
index b6c2b254608..5cbd2ecc997 100644
--- a/components/script/dom/workerglobalscope.rs
+++ b/components/script/dom/workerglobalscope.rs
@@ -91,7 +91,9 @@ pub struct WorkerGlobalScope {
     /// `IpcSender` doesn't exist
     from_devtools_receiver: Receiver<DevtoolScriptControlMsg>,
 
-    microtask_queue: MicrotaskQueue,
+    /// https://html.spec.whatwg.org/multipage/#microtask-queue
+    #[ignore_heap_size_of = "Rc<T> is hard"]
+    microtask_queue: Rc<MicrotaskQueue>,
 
     navigation_start_precise: f64,
     performance: MutNullableJS<Performance>,
diff --git a/components/script/dom/workletglobalscope.rs b/components/script/dom/workletglobalscope.rs
index c01989d746c..28c8cc27e7a 100644
--- a/components/script/dom/workletglobalscope.rs
+++ b/components/script/dom/workletglobalscope.rs
@@ -36,6 +36,7 @@ use script_traits::TimerSchedulerMsg;
 use servo_url::ImmutableOrigin;
 use servo_url::MutableOrigin;
 use servo_url::ServoUrl;
+use std::rc::Rc;
 use std::sync::Arc;
 use std::sync::mpsc::Sender;
 
@@ -46,8 +47,9 @@ pub struct WorkletGlobalScope {
     globalscope: GlobalScope,
     /// The base URL for this worklet.
     base_url: ServoUrl,
-    /// The microtask queue for this worklet
-    microtask_queue: MicrotaskQueue,
+    /// https://html.spec.whatwg.org/multipage/#microtask-queue
+    #[ignore_heap_size_of = "Rc<T> is hard"]
+    microtask_queue: Rc<MicrotaskQueue>,
     /// Sender back to the script thread
     #[ignore_heap_size_of = "channels are hard"]
     to_script_thread_sender: Sender<MainThreadScriptMsg>,
diff --git a/components/script/script_thread.rs b/components/script/script_thread.rs
index a29896f70f5..597d1dce11c 100644
--- a/components/script/script_thread.rs
+++ b/components/script/script_thread.rs
@@ -515,7 +515,8 @@ pub struct ScriptThread {
 
     content_process_shutdown_chan: IpcSender<()>,
 
-    microtask_queue: MicrotaskQueue,
+    /// https://html.spec.whatwg.org/multipage/#microtask-queue
+    microtask_queue: Rc<MicrotaskQueue>,
 
     /// Microtask Queue for adding support for mutation observer microtasks
     mutation_observer_compound_microtask_queued: Cell<bool>,
@@ -892,7 +893,7 @@ impl ScriptThread {
 
             content_process_shutdown_chan: state.content_process_shutdown_chan,
 
-            microtask_queue: MicrotaskQueue::default(),
+            microtask_queue: Default::default(),
 
             mutation_observer_compound_microtask_queued: Default::default(),