diff --git a/src/js.rs b/src/js.rs
index 9ed038c1..fcf9bc85 100644
--- a/src/js.rs
+++ b/src/js.rs
@@ -1042,6 +1042,14 @@ extern "C" {
     /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/has
     #[wasm_bindgen(static_method_of = Reflect, catch)]
     pub fn has(target: &JsValue, property_key: &JsValue) -> Result<JsValue, JsValue>;
+
+    /// The static Reflect.isExtensible() method determines if an object is extensible 
+    /// (whether it can have new properties added to it). It is similar to 
+    /// Object.isExtensible(), but with some differences.
+    /// 
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/isExtensible
+    #[wasm_bindgen(static_method_of = Reflect, js_name = isExtensible, catch)]
+    pub fn is_extensible(target: &Object) -> Result<JsValue, JsValue>;
 }
 
 // Set
diff --git a/tests/all/js_globals/Reflect.rs b/tests/all/js_globals/Reflect.rs
index 9e572877..50ee68d8 100644
--- a/tests/all/js_globals/Reflect.rs
+++ b/tests/all/js_globals/Reflect.rs
@@ -433,4 +433,54 @@ fn has() {
         "#,
         )
         .test()
+}
+
+#[test]
+fn is_extensible() {
+    project()
+        .file(
+            "src/lib.rs",
+            r#"
+            #![feature(proc_macro, wasm_custom_section)]
+
+            extern crate wasm_bindgen;
+            use wasm_bindgen::prelude::*;
+            use wasm_bindgen::js;
+
+            #[wasm_bindgen]
+            pub fn is_extensible(target: &js::Object) -> JsValue {
+                let result = js::Reflect::is_extensible(target);
+                let result = match result {
+                    Ok(val) => val,
+                    Err(_err) => "TypeError".into()
+                };
+                result
+            }
+        "#,
+        )
+        .file(
+            "test.ts",
+            r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                const object = {
+                    property: 42
+                };
+
+                assert.equal(wasm.is_extensible(object), true);
+
+                Reflect.preventExtensions(object);
+
+                assert.equal(wasm.is_extensible(object), false);
+
+                const object2 = Object.seal({});
+
+                assert.equal(wasm.is_extensible(object2), false);
+                assert.equal(wasm.is_extensible(""), "TypeError");
+            }
+        "#,
+        )
+        .test()
 }
\ No newline at end of file