diff --git a/src/backends/wasm_js.rs b/src/backends/wasm_js.rs
index 8c05aa3c..6ccef112 100644
--- a/src/backends/wasm_js.rs
+++ b/src/backends/wasm_js.rs
@@ -65,8 +65,8 @@ pub fn fill_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
 fn is_sab() -> bool {
     use core::sync::atomic::{AtomicU8, Ordering};
 
+    use js_sys::Object;
     use js_sys::WebAssembly::Memory;
-    use js_sys::{Object, SharedArrayBuffer};
     use wasm_bindgen::JsCast;
 
     const MEMORY_KIND_UNINIT: u8 = 0;
@@ -85,19 +85,9 @@ fn is_sab() -> bool {
                 // `SharedArrayBuffer` is only available with COOP & COEP. But even without its
                 // possible to create a shared `WebAssembly.Memory`, so we check for that via
                 // the constructor name.
-                //
-                // Keep in mind that `crossOriginIsolated` is not available on Node.js, in
-                // which case we can still use `instanceof` because `SharedArrayBuffer` is
-                // always available.
-                let shared = match CROSS_ORIGIN_ISOLATED.with(Option::clone) {
-                    Some(true) | None => buffer.is_instance_of::<SharedArrayBuffer>(),
-                    Some(false) => {
-                        let constructor_name = Object::from(buffer).constructor().name();
-                        SHARED_ARRAY_BUFFER_NAME.with(|name| &constructor_name == name)
-                    }
-                };
-
-                let val = if shared {
+                let constructor_name = Object::from(buffer).constructor().name();
+                let val = if SHARED_ARRAY_BUFFER_NAME.with(|sab_name| &constructor_name == sab_name)
+                {
                     MEMORY_KIND_SHARED
                 } else {
                     MEMORY_KIND_NOT_SHARED
@@ -128,9 +118,6 @@ extern "C" {
     fn get_random_values(this: &Crypto, buf: &Uint8Array) -> Result<(), JsValue>;
     #[wasm_bindgen(method, js_name = getRandomValues, catch)]
     fn get_random_values_ref(this: &Crypto, buf: &mut [u8]) -> Result<(), JsValue>;
-    // Returns the [`crossOriginIsolated`](https://developer.mozilla.org/en-US/docs/Web/API/crossOriginIsolated) global property.
-    #[wasm_bindgen(thread_local_v2, js_namespace = globalThis, js_name = crossOriginIsolated)]
-    static CROSS_ORIGIN_ISOLATED: Option<bool>;
     #[wasm_bindgen(thread_local_v2, static_string)]
     static SHARED_ARRAY_BUFFER_NAME: JsString = "SharedArrayBuffer";
 }