diff --git a/src/js.rs b/src/js.rs
index 6e4500608..b623daf88 100644
--- a/src/js.rs
+++ b/src/js.rs
@@ -644,6 +644,12 @@ extern {
     #[wasm_bindgen(method, js_class = "String")]
     pub fn substr(this: &JsString, start: i32, length: i32) -> JsString;
 
+    /// The toString() method returns a string representing the specified object.
+    ///
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/toString
+    #[wasm_bindgen(method, js_class = "String", js_name = toString)]
+    pub fn to_string(this: &JsString) -> JsString;
+
     /// The trim() method removes whitespace from both ends of a string.
     /// Whitespace in this context is all the whitespace characters
     /// (space, tab, no-break space, etc.) and all the line terminator characters (LF, CR, etc.).
@@ -679,6 +685,12 @@ extern {
     /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/trimStart
     #[wasm_bindgen(method, js_class = "String", js_name = trimLeft)]
     pub fn trim_left(this: &JsString) -> JsString;
+
+    /// The valueOf() method returns the primitive value of a String object.
+    ///
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/valueOf
+    #[wasm_bindgen(method, js_class = "String", js_name = valueOf)]
+    pub fn value_of(this: &JsString) -> JsString;
 }
 
 impl<'a> From<&'a str> for JsString {
diff --git a/tests/all/js_globals/JsString.rs b/tests/all/js_globals/JsString.rs
index 190adf9e6..07579b7c7 100644
--- a/tests/all/js_globals/JsString.rs
+++ b/tests/all/js_globals/JsString.rs
@@ -360,6 +360,33 @@ fn substr() {
         .test()
 }
 
+#[test]
+fn to_string() {
+    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 string_to_string(this: &js::JsString) -> js::JsString {
+                this.to_string()
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                let greeting = 'Hello world!';
+                assert.equal(wasm.string_to_string(greeting), 'Hello world!');
+            }
+        "#)
+        .test()
+}
+
 #[test]
 fn trim() {
     project()
@@ -454,4 +481,31 @@ fn trim_start_and_trim_left() {
             }
         "#)
         .test()
+}
+
+#[test]
+fn value_of() {
+    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 string_value_of(this: &js::JsString) -> js::JsString {
+                this.value_of()
+            }
+        "#)
+        .file("test.ts", r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                let greeting = new String('Hello world!');
+                assert.equal(wasm.string_value_of(greeting), 'Hello world!');
+            }
+        "#)
+        .test()
 }
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