diff --git a/ext/napi/lib.rs b/ext/napi/lib.rs
index b4f38fd0af..789aec5eb7 100644
--- a/ext/napi/lib.rs
+++ b/ext/napi/lib.rs
@@ -11,6 +11,7 @@ use deno_core::error::AnyError;
 use deno_core::futures::channel::mpsc;
 use deno_core::futures::StreamExt;
 use deno_core::op;
+use deno_core::parking_lot::Mutex;
 use deno_core::serde_v8;
 use deno_core::Extension;
 use deno_core::OpState;
@@ -338,7 +339,7 @@ pub struct NapiState {
     mpsc::UnboundedSender<ThreadSafeFunctionStatus>,
   pub env_cleanup_hooks:
     Rc<RefCell<Vec<(extern "C" fn(*const c_void), *const c_void)>>>,
-  pub tsfn_ref_counters: Rc<RefCell<ThreadsafeFunctionRefCounters>>,
+  pub tsfn_ref_counters: Arc<Mutex<ThreadsafeFunctionRefCounters>>,
 }
 
 impl Drop for NapiState {
@@ -415,7 +416,7 @@ pub struct Env {
     mpsc::UnboundedSender<ThreadSafeFunctionStatus>,
   pub cleanup_hooks:
     Rc<RefCell<Vec<(extern "C" fn(*const c_void), *const c_void)>>>,
-  pub tsfn_ref_counters: Rc<RefCell<ThreadsafeFunctionRefCounters>>,
+  pub tsfn_ref_counters: Arc<Mutex<ThreadsafeFunctionRefCounters>>,
   pub last_error: napi_extended_error_info,
 }
 
@@ -431,7 +432,7 @@ impl Env {
     cleanup_hooks: Rc<
       RefCell<Vec<(extern "C" fn(*const c_void), *const c_void)>>,
     >,
-    tsfn_ref_counters: Rc<RefCell<ThreadsafeFunctionRefCounters>>,
+    tsfn_ref_counters: Arc<Mutex<ThreadsafeFunctionRefCounters>>,
   ) -> Self {
     let sc = sender.clone();
     ASYNC_WORK_SENDER.with(|s| {
@@ -498,13 +499,13 @@ impl Env {
     id: usize,
     counter: Arc<AtomicUsize>,
   ) {
-    let mut counters = self.tsfn_ref_counters.borrow_mut();
+    let mut counters = self.tsfn_ref_counters.lock();
     assert!(!counters.iter().any(|(i, _)| *i == id));
     counters.push((id, counter));
   }
 
   pub fn remove_threadsafe_function_ref_counter(&mut self, id: usize) {
-    let mut counters = self.tsfn_ref_counters.borrow_mut();
+    let mut counters = self.tsfn_ref_counters.lock();
     let index = counters.iter().position(|(i, _)| *i == id).unwrap();
     counters.remove(index);
   }
@@ -533,7 +534,7 @@ pub fn init<P: NapiPermissions + 'static>(unstable: bool) -> Extension {
           maybe_scheduling = true;
         }
 
-        let tsfn_ref_counters = napi_state.tsfn_ref_counters.borrow().clone();
+        let tsfn_ref_counters = napi_state.tsfn_ref_counters.lock().clone();
         for (_id, counter) in tsfn_ref_counters.iter() {
           if counter.load(std::sync::atomic::Ordering::SeqCst) > 0 {
             maybe_scheduling = true;
@@ -572,7 +573,7 @@ pub fn init<P: NapiPermissions + 'static>(unstable: bool) -> Extension {
         threadsafe_function_receiver,
         active_threadsafe_functions: 0,
         env_cleanup_hooks: Rc::new(RefCell::new(vec![])),
-        tsfn_ref_counters: Rc::new(RefCell::new(vec![])),
+        tsfn_ref_counters: Arc::new(Mutex::new(vec![])),
       });
       state.put(Unstable(unstable));
       Ok(())